diff --git a/mailpoet/tests/integration/API/JSON/v1/CustomFieldsTest.php b/mailpoet/tests/integration/API/JSON/v1/CustomFieldsTest.php
index 2883bc998c..51be977866 100644
--- a/mailpoet/tests/integration/API/JSON/v1/CustomFieldsTest.php
+++ b/mailpoet/tests/integration/API/JSON/v1/CustomFieldsTest.php
@@ -90,7 +90,7 @@ class CustomFieldsTest extends \MailPoetTest {
     verify($response->status)->equals(APIResponse::STATUS_OK);
 
     $customField = $this->repository->findOneBy(['type' => 'date']);
-    expect($customField)->null();
+    verify($customField)->null();
 
     $response = $this->endpoint->delete(['id' => $customFieldId]);
     verify($response->status)->equals(APIResponse::STATUS_NOT_FOUND);
diff --git a/mailpoet/tests/integration/API/JSON/v1/DynamicSegmentsTest.php b/mailpoet/tests/integration/API/JSON/v1/DynamicSegmentsTest.php
index 7f306a94b2..0746b49f3b 100644
--- a/mailpoet/tests/integration/API/JSON/v1/DynamicSegmentsTest.php
+++ b/mailpoet/tests/integration/API/JSON/v1/DynamicSegmentsTest.php
@@ -135,7 +135,7 @@ class DynamicSegmentsTest extends \MailPoetTest {
 
     $this->entityManager->refresh($dynamicSegment);
     $this->assertInstanceOf(SegmentEntity::class, $dynamicSegment);
-    expect($dynamicSegment->getDeletedAt())->null();
+    verify($dynamicSegment->getDeletedAt())->null();
   }
 
   public function testItCanDeleteASegment() {
@@ -152,8 +152,8 @@ class DynamicSegmentsTest extends \MailPoetTest {
     // Clear entity manager to forget all entities
     $this->entityManager->clear();
 
-    expect($this->entityManager->find(SegmentEntity::class, $dynamicSegment->getId()))->null();
-    expect($this->entityManager->find(DynamicSegmentFilterEntity::class, $dynamicSegmentFilter->getId()))->null();
+    verify($this->entityManager->find(SegmentEntity::class, $dynamicSegment->getId()))->null();
+    verify($this->entityManager->find(DynamicSegmentFilterEntity::class, $dynamicSegmentFilter->getId()))->null();
   }
 
   public function testItCanBulkDeleteSegments() {
@@ -182,8 +182,8 @@ class DynamicSegmentsTest extends \MailPoetTest {
 
     $this->entityManager->refresh($dynamicSegment1);
     $this->entityManager->refresh($dynamicSegment2);
-    expect($dynamicSegment1->getDeletedAt())->null();
-    expect($dynamicSegment2->getDeletedAt())->null();
+    verify($dynamicSegment1->getDeletedAt())->null();
+    verify($dynamicSegment2->getDeletedAt())->null();
 
     $this->endpoint->bulkAction([
       'action' => 'trash',
@@ -207,8 +207,8 @@ class DynamicSegmentsTest extends \MailPoetTest {
 
     $this->entityManager->clear();
 
-    expect($this->entityManager->find(SegmentEntity::class, $dynamicSegment1->getId()))->null();
-    expect($this->entityManager->find(SegmentEntity::class, $dynamicSegment2->getId()))->null();
+    verify($this->entityManager->find(SegmentEntity::class, $dynamicSegment1->getId()))->null();
+    verify($this->entityManager->find(SegmentEntity::class, $dynamicSegment2->getId()))->null();
   }
 
   private function createDynamicSegmentEntity(string $name, string $description): SegmentEntity {
diff --git a/mailpoet/tests/integration/API/JSON/v1/FormsTest.php b/mailpoet/tests/integration/API/JSON/v1/FormsTest.php
index 4d165353ea..e4c56dd3c5 100644
--- a/mailpoet/tests/integration/API/JSON/v1/FormsTest.php
+++ b/mailpoet/tests/integration/API/JSON/v1/FormsTest.php
@@ -221,7 +221,7 @@ class FormsTest extends \MailPoetTest {
     verify($response->data)->equals(
       $this->form1->toArray()
     );
-    expect($response->data['deleted_at'])->null();
+    verify($response->data['deleted_at'])->null();
     verify($response->meta['count'])->equals(1);
   }
 
diff --git a/mailpoet/tests/integration/API/JSON/v1/MailerTest.php b/mailpoet/tests/integration/API/JSON/v1/MailerTest.php
index ab231767d1..be9c526446 100644
--- a/mailpoet/tests/integration/API/JSON/v1/MailerTest.php
+++ b/mailpoet/tests/integration/API/JSON/v1/MailerTest.php
@@ -30,7 +30,7 @@ class MailerTest extends \MailPoetTest {
     $response = $mailerEndpoint->resumeSending();
     verify($response->status)->equals(APIResponse::STATUS_OK);
     $mailerLog = MailerLog::getMailerLog();
-    expect($mailerLog['status'])->null();
+    verify($mailerLog['status'])->null();
   }
 
   public function testItRunsAuhtorizedEmailsCheckIfErrorIsPresent() {
diff --git a/mailpoet/tests/integration/API/JSON/v1/NewsletterTemplatesTest.php b/mailpoet/tests/integration/API/JSON/v1/NewsletterTemplatesTest.php
index 1146265210..9759eb9d74 100644
--- a/mailpoet/tests/integration/API/JSON/v1/NewsletterTemplatesTest.php
+++ b/mailpoet/tests/integration/API/JSON/v1/NewsletterTemplatesTest.php
@@ -130,6 +130,6 @@ class NewsletterTemplatesTest extends \MailPoetTest {
     verify($response->status)->equals(APIResponse::STATUS_OK);
 
     $deletedTemplate = $this->newsletterTemplatesRepository->findOneById($templateId);
-    expect($deletedTemplate)->null();
+    verify($deletedTemplate)->null();
   }
 }
diff --git a/mailpoet/tests/integration/API/JSON/v1/NewslettersTest.php b/mailpoet/tests/integration/API/JSON/v1/NewslettersTest.php
index 20a1d4cd86..891d3d4457 100644
--- a/mailpoet/tests/integration/API/JSON/v1/NewslettersTest.php
+++ b/mailpoet/tests/integration/API/JSON/v1/NewslettersTest.php
@@ -332,7 +332,7 @@ class NewslettersTest extends \MailPoetTest {
     $newsletter = $this->newsletterRepository->findOneById($this->newsletter->getId());
     $this->assertInstanceOf(NewsletterEntity::class, $newsletter);
     verify($response->data)->equals($this->newslettersResponseBuilder->build($newsletter));
-    expect($response->data['deleted_at'])->null();
+    verify($response->data['deleted_at'])->null();
     verify($response->meta['count'])->equals(1);
   }
 
diff --git a/mailpoet/tests/integration/API/JSON/v1/SegmentsTest.php b/mailpoet/tests/integration/API/JSON/v1/SegmentsTest.php
index 9295eb6ec2..770d0eb7c7 100644
--- a/mailpoet/tests/integration/API/JSON/v1/SegmentsTest.php
+++ b/mailpoet/tests/integration/API/JSON/v1/SegmentsTest.php
@@ -130,7 +130,7 @@ class SegmentsTest extends \MailPoetTest {
     verify($response->data)->equals(
       $this->responseBuilder->build($segment)
     );
-    expect($response->data['deleted_at'])->null();
+    verify($response->data['deleted_at'])->null();
     verify($response->meta['count'])->equals(1);
   }
 
diff --git a/mailpoet/tests/integration/API/JSON/v1/ServicesTest.php b/mailpoet/tests/integration/API/JSON/v1/ServicesTest.php
index 81ceb90972..292fcfaf2b 100644
--- a/mailpoet/tests/integration/API/JSON/v1/ServicesTest.php
+++ b/mailpoet/tests/integration/API/JSON/v1/ServicesTest.php
@@ -403,8 +403,8 @@ class ServicesTest extends \MailPoetTest {
     $servicesEndpoint = $this->createServicesEndpointWithMocks(['bridge' => $bridge]);
     $response = $servicesEndpoint->checkMSSKey($this->data);
 
-    expect($this->settings->get('public_id', null))->null();
-    expect($this->settings->get('new_public_id', null))->null();
+    verify($this->settings->get('public_id', null))->null();
+    verify($this->settings->get('new_public_id', null))->null();
   }
 
   public function testItRespondsWithPublicIdForPremium() {
@@ -445,8 +445,8 @@ class ServicesTest extends \MailPoetTest {
     $servicesEndpoint = $this->createServicesEndpointWithMocks(['bridge' => $bridge]);
     $response = $servicesEndpoint->checkPremiumKey($this->data);
 
-    expect($this->settings->get('public_id', null))->null();
-    expect($this->settings->get('new_public_id', null))->null();
+    verify($this->settings->get('public_id', null))->null();
+    verify($this->settings->get('new_public_id', null))->null();
   }
 
   public function testCongratulatoryEmailIsSent() {
diff --git a/mailpoet/tests/integration/API/JSON/v1/SettingsTest.php b/mailpoet/tests/integration/API/JSON/v1/SettingsTest.php
index 24326f814d..c777659a8c 100644
--- a/mailpoet/tests/integration/API/JSON/v1/SettingsTest.php
+++ b/mailpoet/tests/integration/API/JSON/v1/SettingsTest.php
@@ -242,7 +242,7 @@ class SettingsTest extends \MailPoetTest {
         'status' => ScheduledTaskEntity::STATUS_SCHEDULED,
       ]
     );
-    expect($task)->null();
+    verify($task)->null();
 
     $settings = ['deactivate_subscriber_after_inactive_days' => 0];
     $this->endpoint->set($settings);
@@ -302,7 +302,7 @@ class SettingsTest extends \MailPoetTest {
     $this->settings->set('setting_to_be_deleted', true);
     $response = $this->endpoint->delete('setting_to_be_deleted');
     expect($response)->isInstanceOf(SuccessResponse::class);
-    expect($this->settings->get('setting_to_be_deleted'))->null();
+    verify($this->settings->get('setting_to_be_deleted'))->null();
   }
 
   public function testDeleteReturnErrorForEmptySettingName() {
diff --git a/mailpoet/tests/integration/API/JSON/v1/SubscribersTest.php b/mailpoet/tests/integration/API/JSON/v1/SubscribersTest.php
index feaa480bc5..f5aab774d2 100644
--- a/mailpoet/tests/integration/API/JSON/v1/SubscribersTest.php
+++ b/mailpoet/tests/integration/API/JSON/v1/SubscribersTest.php
@@ -331,7 +331,7 @@ class SubscribersTest extends \MailPoetTest {
     verify($response->data['id'])->equals($subscriber->getId());
     verify($response->data['email'])->equals($subscriber->getEmail());
     verify($response->data['status'])->equals($subscriber->getStatus());
-    expect($response->data['deleted_at'])->null();
+    verify($response->data['deleted_at'])->null();
     verify($response->meta['count'])->equals(1);
   }
 
@@ -904,7 +904,7 @@ class SubscribersTest extends \MailPoetTest {
     ]);
 
     $didSubscribe = $this->subscribersRepository->findOneBy(['email' => 'toto@mailpoet.com']);
-    expect($didSubscribe)->null();
+    verify($didSubscribe)->null();
     expect($response)->isInstanceOf(ErrorResponse::class);
     verify($response->status)->equals(APIResponse::STATUS_BAD_REQUEST);
     verify($response->errors[0]['message'])->equals($expectedErrorMessage);
@@ -1083,8 +1083,8 @@ class SubscribersTest extends \MailPoetTest {
 
     verify($response->status)->equals(APIResponse::STATUS_OK);
     verify($response->meta['count'])->equals(2);
-    expect($subscriberTag1)->null();
-    expect($subscriberTag2)->null();
+    verify($subscriberTag1)->null();
+    verify($subscriberTag2)->null();
 
     // Testing that removing the same tag again does not return an error
     $response = $this->endpoint->bulkAction($bulkActionData);
diff --git a/mailpoet/tests/integration/API/MP/SegmentsTest.php b/mailpoet/tests/integration/API/MP/SegmentsTest.php
index 8e6f328f4e..a508ee09ed 100644
--- a/mailpoet/tests/integration/API/MP/SegmentsTest.php
+++ b/mailpoet/tests/integration/API/MP/SegmentsTest.php
@@ -247,7 +247,7 @@ class SegmentsTest extends \MailPoetTest {
     $result = $this->getApi()->deleteList($segmentId);
     verify($result)->equals(true);
     $this->entityManager->clear();
-    expect($this->segmentsRepository->findOneById($segmentId))->null();
+    verify($this->segmentsRepository->findOneById($segmentId))->null();
     expect($this->subscriberSegmentsRepository->findBy(['segment' => $segmentId]))->count(0);
   }
 
diff --git a/mailpoet/tests/integration/Analytics/AnalyticsTest.php b/mailpoet/tests/integration/Analytics/AnalyticsTest.php
index f640c331b3..97a8bbe875 100644
--- a/mailpoet/tests/integration/Analytics/AnalyticsTest.php
+++ b/mailpoet/tests/integration/Analytics/AnalyticsTest.php
@@ -51,7 +51,7 @@ class AnalyticsTest extends \MailPoetTest {
     $this->settings->set('analytics', ['enabled' => '']);
     $analytics = new Analytics($reporter, SettingsController::getInstance());
 
-    expect($analytics->generateAnalytics())->null();
+    verify($analytics->generateAnalytics())->null();
   }
 
   public function testGetDataIfSentRecently() {
@@ -66,7 +66,7 @@ class AnalyticsTest extends \MailPoetTest {
     $this->settings->set('analytics_last_sent', Carbon::now()->subHours(1));
     $analytics = new Analytics($reporter, SettingsController::getInstance());
 
-    expect($analytics->generateAnalytics())->null();
+    verify($analytics->generateAnalytics())->null();
   }
 
   public function testGetDataIfEnabledButNeverSent() {
@@ -116,7 +116,7 @@ class AnalyticsTest extends \MailPoetTest {
 
     verify($this->settings->get('public_id'))->equals($fakePublicId);
     verify($this->settings->get('new_public_id'))->equals('true');
-    expect($this->settings->get(Analytics::SETTINGS_LAST_SENT_KEY, null))->null();
+    verify($this->settings->get(Analytics::SETTINGS_LAST_SENT_KEY, null))->null();
   }
 
   public function testIsPublicIdNew() {
diff --git a/mailpoet/tests/integration/AutomaticEmails/AutomaticEmailsTest.php b/mailpoet/tests/integration/AutomaticEmails/AutomaticEmailsTest.php
index 70a3138a9c..63c0915727 100644
--- a/mailpoet/tests/integration/AutomaticEmails/AutomaticEmailsTest.php
+++ b/mailpoet/tests/integration/AutomaticEmails/AutomaticEmailsTest.php
@@ -47,7 +47,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
     expect($result)->hasKey('email1');
     $this->AM->unregisterAutomaticEmails();
     $result = $this->AM->getAutomaticEmails();
-    expect($result)->null();
+    verify($result)->null();
   }
 
   public function testItGetsAutomaticEmails() {
@@ -93,7 +93,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
   }
 
   public function testItReturnsNullWhenGettingEmailBySlugAndThereAreNoRegisteredEmails() {
-    expect($this->AM->getAutomaticEmailBySlug('some_slug'))->null();
+    verify($this->AM->getAutomaticEmailBySlug('some_slug'))->null();
 
   }
 
@@ -114,7 +114,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
       ];
     });
 
-    expect($this->AM->getAutomaticEmailBySlug('some_slug'))->null();
+    verify($this->AM->getAutomaticEmailBySlug('some_slug'))->null();
 
     $this->wp->removeAllFilters('mailpoet_automatic_email_test');
   }
@@ -159,7 +159,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
   }
 
   public function testItReturnsNullWhenGettingEmailEventBySlugAndThereAreNoRegisteredEmails() {
-    expect($this->AM->getAutomaticEmailEventBySlug('some_email', 'some_slug'))->null();
+    verify($this->AM->getAutomaticEmailEventBySlug('some_email', 'some_slug'))->null();
   }
 
   public function testItReturnsNullWhenItCannotGetEmailEventBySlug() {
@@ -179,7 +179,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
       ];
     });
 
-    expect($this->AM->getAutomaticEmailEventBySlug('emai', 'some_slug'))->null();
+    verify($this->AM->getAutomaticEmailEventBySlug('emai', 'some_slug'))->null();
 
     $this->wp->removeAllFilters('mailpoet_automatic_email_test');
   }
diff --git a/mailpoet/tests/integration/Automation/Engine/Storage/AutomationStorageTest.php b/mailpoet/tests/integration/Automation/Engine/Storage/AutomationStorageTest.php
index 7bcd5ee006..e452274401 100644
--- a/mailpoet/tests/integration/Automation/Engine/Storage/AutomationStorageTest.php
+++ b/mailpoet/tests/integration/Automation/Engine/Storage/AutomationStorageTest.php
@@ -153,7 +153,7 @@ class AutomationStorageTest extends \MailPoetTest {
     expect($this->testee->getAutomations())->count(2);
     $this->testee->deleteAutomation($automationToDelete);
     expect($this->testee->getAutomations())->count(1);
-    expect($this->testee->getAutomation($automationToDelete->getId()))->null();
+    verify($this->testee->getAutomation($automationToDelete->getId()))->null();
     $automationToKeepFromDatabase = $this->testee->getAutomation($automationToKeep->getId());
     $this->assertInstanceOf(Automation::class, $automationToKeepFromDatabase);
     expect($automationToKeepFromDatabase->getVersionId())->notNull();
@@ -188,13 +188,13 @@ class AutomationStorageTest extends \MailPoetTest {
     }
     $this->testee->deleteAutomation($automations['toDelete']);
     foreach ($runs['toDelete'] as $runId) {
-      expect($automationRunStorage->getAutomationRun($runId))->null();
+      verify($automationRunStorage->getAutomationRun($runId))->null();
     }
     foreach ($runs['toKeep'] as $runId) {
       expect($automationRunStorage->getAutomationRun($runId))->notNull();
     }
     foreach ($runLogs['toDelete'] as $runLogId) {
-      expect($automationRunLogStorage->getAutomationRunLog($runLogId))->null();
+      verify($automationRunLogStorage->getAutomationRunLog($runLogId))->null();
     }
     foreach ($runLogs['toKeep'] as $runLogId) {
       expect($automationRunLogStorage->getAutomationRunLog($runLogId))->notNull();
diff --git a/mailpoet/tests/integration/Config/CapabilitiesTest.php b/mailpoet/tests/integration/Config/CapabilitiesTest.php
index 543b3f43f4..250c74b5d1 100644
--- a/mailpoet/tests/integration/Config/CapabilitiesTest.php
+++ b/mailpoet/tests/integration/Config/CapabilitiesTest.php
@@ -79,7 +79,7 @@ class CapabilitiesTest extends \MailPoetTest {
     $this->caps->setupWPCapabilities();
 
     // role does not exist
-    expect(get_role('nonexistent_role'))->null();
+    verify(get_role('nonexistent_role'))->null();
 
     // other MailPoet capabilities were successfully configured
     $editorRole = get_role('editor');
diff --git a/mailpoet/tests/integration/Config/EnvTest.php b/mailpoet/tests/integration/Config/EnvTest.php
index fdb8071d52..fb789dcf93 100644
--- a/mailpoet/tests/integration/Config/EnvTest.php
+++ b/mailpoet/tests/integration/Config/EnvTest.php
@@ -29,7 +29,7 @@ class EnvTest extends \MailPoetTest {
   public function testItProcessDBHost() {
     Env::init('file', '1.0.0', 'localhost', 'db_user', 'pass123', 'db_name');
     verify(Env::$dbHost)->equals('localhost');
-    expect(Env::$dbPort)->null();
+    verify(Env::$dbPort)->null();
 
     Env::init('file', '1.0.0', 'localhost:3307', 'db_user', 'pass123', 'db_name');
     verify(Env::$dbHost)->equals('localhost');
diff --git a/mailpoet/tests/integration/Config/ServicesCheckerTest.php b/mailpoet/tests/integration/Config/ServicesCheckerTest.php
index 073cfc9d9c..9534167256 100644
--- a/mailpoet/tests/integration/Config/ServicesCheckerTest.php
+++ b/mailpoet/tests/integration/Config/ServicesCheckerTest.php
@@ -26,7 +26,7 @@ class ServicesCheckerTest extends \MailPoetTest {
   public function testItDoesNotCheckMSSKeyIfMPSendingServiceIsDisabled() {
     $this->disableMailPoetSendingMethod();
     $result = $this->servicesChecker->isMailPoetAPIKeyValid();
-    expect($result)->null();
+    verify($result)->null();
   }
 
   public function testItForciblyChecksMSSKeyIfMPSendingServiceIsDisabled() {
@@ -248,7 +248,7 @@ class ServicesCheckerTest extends \MailPoetTest {
         'state' => '',
       ]
     );
-    expect($this->servicesChecker->getValidAccountKey())->null();
+    verify($this->servicesChecker->getValidAccountKey())->null();
   }
 
   public function testItReturnsTrueIfUserIsActivelyPaying() {
diff --git a/mailpoet/tests/integration/Config/ShortcodesTest.php b/mailpoet/tests/integration/Config/ShortcodesTest.php
index c2efba1011..8cf262a87c 100644
--- a/mailpoet/tests/integration/Config/ShortcodesTest.php
+++ b/mailpoet/tests/integration/Config/ShortcodesTest.php
@@ -342,7 +342,7 @@ class ShortcodesTest extends \MailPoetTest {
     $wpUser = wp_set_current_user(1);
     verify((new WPFunctions)->isUserLoggedIn())->true();
 
-    expect($this->subscribersRepository->findOneBy(['email' => $wpUser->user_email]))->null(); // phpcs:ignore Squiz.NamingConventions.ValidVariableName.MemberNotCamelCaps
+    verify($this->subscribersRepository->findOneBy(['email' => $wpUser->user_email]))->null(); // phpcs:ignore Squiz.NamingConventions.ValidVariableName.MemberNotCamelCaps
 
     $shortcodes = ContainerWrapper::getInstance()->get(Shortcodes::class);
     $shortcodes->init();
@@ -378,7 +378,7 @@ class ShortcodesTest extends \MailPoetTest {
   public function testItDoesNotDisplayLinkToManageSubscriptionPageForLoggedinNonexistentSubscribers() {
     $wpUser = wp_set_current_user(1);
     verify((new WPFunctions)->isUserLoggedIn())->true();
-    expect($this->subscribersRepository->findOneBy(['email' => $wpUser->user_email]))->null(); // phpcs:ignore Squiz.NamingConventions.ValidVariableName.MemberNotCamelCaps
+    verify($this->subscribersRepository->findOneBy(['email' => $wpUser->user_email]))->null(); // phpcs:ignore Squiz.NamingConventions.ValidVariableName.MemberNotCamelCaps
 
     $shortcodes = ContainerWrapper::getInstance()->get(Shortcodes::class);
     $shortcodes->init();
diff --git a/mailpoet/tests/integration/Cron/CronHelperTest.php b/mailpoet/tests/integration/Cron/CronHelperTest.php
index 9484b44b57..04bb06124b 100644
--- a/mailpoet/tests/integration/Cron/CronHelperTest.php
+++ b/mailpoet/tests/integration/Cron/CronHelperTest.php
@@ -174,7 +174,7 @@ class CronHelperTest extends \MailPoetTest {
         CronHelper::DAEMON_SETTING,
         $daemon
       );
-      expect($this->cronHelper->isDaemonAccessible())->null();
+      verify($this->cronHelper->isDaemonAccessible())->null();
     }
   }
 
@@ -259,7 +259,7 @@ class CronHelperTest extends \MailPoetTest {
 
   public function testItEnforcesExecutionLimit() {
     $time = microtime(true);
-    expect($this->cronHelper->enforceExecutionLimit($time))->null();
+    verify($this->cronHelper->enforceExecutionLimit($time))->null();
     try {
       $this->cronHelper->enforceExecutionLimit($time - $this->cronHelper->getDaemonExecutionLimit());
       self::fail('Execution limit exception not thrown.');
diff --git a/mailpoet/tests/integration/Cron/CronWorkerRunnerTest.php b/mailpoet/tests/integration/Cron/CronWorkerRunnerTest.php
index 892defa9f1..a063fd3df7 100644
--- a/mailpoet/tests/integration/Cron/CronWorkerRunnerTest.php
+++ b/mailpoet/tests/integration/Cron/CronWorkerRunnerTest.php
@@ -192,7 +192,7 @@ class CronWorkerRunnerTest extends \MailPoetTest {
       $task = $this->scheduledTasksRepository->findOneById($task->getId());
       $this->assertInstanceOf(ScheduledTaskEntity::class, $task);
       verify($scheduledAt)->equals($task->getScheduledAt());
-      expect($task->getStatus())->null();
+      verify($task->getStatus())->null();
       verify($task->getRescheduleCount())->equals(0);
     }
   }
diff --git a/mailpoet/tests/integration/Cron/CronWorkerSchedulerTest.php b/mailpoet/tests/integration/Cron/CronWorkerSchedulerTest.php
index d8ce486e67..e2c33cfb75 100644
--- a/mailpoet/tests/integration/Cron/CronWorkerSchedulerTest.php
+++ b/mailpoet/tests/integration/Cron/CronWorkerSchedulerTest.php
@@ -51,7 +51,7 @@ class CronWorkerSchedulerTest extends \MailPoetTest {
     verify($immediateTask->getId())->equals($task->getId());
     expect($tasks)->count(1);
     expect($tasks[0]->getType())->same('test');
-    expect($tasks[0]->getStatus())->null();
+    verify($tasks[0]->getStatus())->null();
     expect($tasks[0]->getScheduledAt())->same($nextRunDate);
   }
 
diff --git a/mailpoet/tests/integration/Cron/DaemonTest.php b/mailpoet/tests/integration/Cron/DaemonTest.php
index f851e2421a..811666a08c 100644
--- a/mailpoet/tests/integration/Cron/DaemonTest.php
+++ b/mailpoet/tests/integration/Cron/DaemonTest.php
@@ -85,7 +85,7 @@ class DaemonTest extends \MailPoetTest {
     $daemon = new Daemon($this->cronHelper, $cronWorkerRunner, $factoryMock, $this->diContainer->get(LoggerFactory::class));
     $daemon->run($data);
     $log = $this->logRepository->findOneBy(['name' => 'cron', 'level' => 400]);
-    expect($log)->null();
+    verify($log)->null();
     $this->wp->removeFilter('mailpoet_cron_get_execution_limit', $limitCallback);
   }
 
diff --git a/mailpoet/tests/integration/Cron/SupervisorTest.php b/mailpoet/tests/integration/Cron/SupervisorTest.php
index 1c20931fae..f66351a689 100644
--- a/mailpoet/tests/integration/Cron/SupervisorTest.php
+++ b/mailpoet/tests/integration/Cron/SupervisorTest.php
@@ -36,7 +36,7 @@ class SupervisorTest extends \MailPoetTest {
 
   public function testItCreatesDaemonWhenOneDoesNotExist() {
     if (getenv('WP_TEST_ENABLE_NETWORK_TESTS') !== 'true') $this->markTestSkipped();
-    expect($this->settings->get(CronHelper::DAEMON_SETTING))->null();
+    verify($this->settings->get(CronHelper::DAEMON_SETTING))->null();
     $this->supervisor->init();
     expect($this->supervisor->getDaemon())->notEmpty();
   }
diff --git a/mailpoet/tests/integration/Cron/Triggers/WordPressTest.php b/mailpoet/tests/integration/Cron/Triggers/WordPressTest.php
index a9b63ea3ee..d420ae0dbb 100644
--- a/mailpoet/tests/integration/Cron/Triggers/WordPressTest.php
+++ b/mailpoet/tests/integration/Cron/Triggers/WordPressTest.php
@@ -171,7 +171,7 @@ class WordPressTest extends \MailPoetTest {
     // status of 'null' indicates that queue is running
     $this->addQueue(null);
     // check that cron daemon does not exist
-    expect($this->settings->get(CronHelper::DAEMON_SETTING))->null();
+    verify($this->settings->get(CronHelper::DAEMON_SETTING))->null();
     $this->wordpressTrigger->run();
     expect($this->settings->get(CronHelper::DAEMON_SETTING))->notNull();
   }
@@ -186,7 +186,7 @@ class WordPressTest extends \MailPoetTest {
   public function testItDoesNotTriggerCronWhenFutureStatsReportIsScheduled() {
     $future = Carbon::now()->addHour();
     $statsJobType = SubscribersStatsReport::TASK_TYPE;
-    expect($this->settings->get(CronHelper::DAEMON_SETTING))->null();
+    verify($this->settings->get(CronHelper::DAEMON_SETTING))->null();
     $scheduledTaskTable = $this->entityManager->getClassMetadata(ScheduledTaskEntity::class)->getTableName();
     $this->entityManager->getConnection()->executeStatement("DELETE FROM $scheduledTaskTable WHERE type = '$statsJobType';");
     $this->settings->set(Bridge::API_KEY_SETTING_NAME, 'asdfgh');
@@ -198,7 +198,7 @@ class WordPressTest extends \MailPoetTest {
 
   public function testItDoesNotTriggerCronForStatsReportIfThereIsNoValidKey() {
     $statsJobType = SubscribersStatsReport::TASK_TYPE;
-    expect($this->settings->get(CronHelper::DAEMON_SETTING))->null();
+    verify($this->settings->get(CronHelper::DAEMON_SETTING))->null();
     $scheduledTaskTable = $this->entityManager->getClassMetadata(ScheduledTaskEntity::class)->getTableName();
     $this->entityManager->getConnection()->executeStatement("DELETE FROM $scheduledTaskTable WHERE type = '$statsJobType';");
     $this->settings->set(Bridge::API_KEY_SETTING_NAME, 'somekey');
@@ -209,7 +209,7 @@ class WordPressTest extends \MailPoetTest {
 
   public function testItTriggersCronIfThereIsValidKeyAndNoStatsReportJobScheduled() {
     $statsJobType = SubscribersStatsReport::TASK_TYPE;
-    expect($this->settings->get(CronHelper::DAEMON_SETTING))->null();
+    verify($this->settings->get(CronHelper::DAEMON_SETTING))->null();
     $scheduledTaskTable = $this->entityManager->getClassMetadata(ScheduledTaskEntity::class)->getTableName();
     $this->entityManager->getConnection()->executeStatement("DELETE FROM $scheduledTaskTable WHERE type = '$statsJobType';");
     $this->settings->set(Bridge::API_KEY_SETTING_NAME, 'somekey');
diff --git a/mailpoet/tests/integration/Cron/Workers/SchedulerTest.php b/mailpoet/tests/integration/Cron/Workers/SchedulerTest.php
index 6ce7443743..aae42c8fe4 100644
--- a/mailpoet/tests/integration/Cron/Workers/SchedulerTest.php
+++ b/mailpoet/tests/integration/Cron/Workers/SchedulerTest.php
@@ -203,7 +203,7 @@ class SchedulerTest extends \MailPoetTest {
 
     $newsletter = $this->newslettersRepository->findOneById($newsletter->getId());
     $this->assertInstanceOf(NewsletterEntity::class, $newsletter);
-    expect($queue->scheduledAt)->null();
+    verify($queue->scheduledAt)->null();
 
     $this->newsletterOptionFactory->create($newsletter, NewsletterOptionFieldEntity::NAME_SCHEDULE, '0 5 * * *');
 
@@ -341,7 +341,7 @@ class SchedulerTest extends \MailPoetTest {
     $this->assertInstanceOf(SendingQueueEntity::class, $sendingQueue);
     $scheduledTask = $this->scheduledTasksRepository->findOneBySendingQueue($sendingQueue);
     $this->assertInstanceOf(ScheduledTaskEntity::class, $scheduledTask);
-    expect($scheduledTask->getStatus())->null();
+    verify($scheduledTask->getStatus())->null();
   }
 
   public function testItProcessesWelcomeNewsletterWhenWPUserIsVerified() {
@@ -362,7 +362,7 @@ class SchedulerTest extends \MailPoetTest {
     $this->assertInstanceOf(SendingQueueEntity::class, $sendingQueue);
     $scheduledTask = $this->scheduledTasksRepository->findOneBySendingQueue($sendingQueue);
     $this->assertInstanceOf(ScheduledTaskEntity::class, $scheduledTask);
-    expect($scheduledTask->getStatus())->null();
+    verify($scheduledTask->getStatus())->null();
   }
 
   public function testItFailsMailpoetSubscriberVerificationWhenSubscriberDoesNotExist() {
@@ -444,7 +444,7 @@ class SchedulerTest extends \MailPoetTest {
     $result = $scheduler->verifyMailpoetSubscriber((int)$subscriber->getId(), $newsletter, $queue);
     verify($result)->false();
     // update the time queue is scheduled to run at
-    expect($this->sendingQueuesRepository->findOneById($queue->id))->null();
+    verify($this->sendingQueuesRepository->findOneById($queue->id))->null();
   }
 
   public function testItCanVerifyMailpoetSubscriber() {
@@ -488,7 +488,7 @@ class SchedulerTest extends \MailPoetTest {
     }, $updatedSubscribers);
     verify($updatedSubscribersIds)->equals([$subscriber->getId()]);
     // set queue's status to null
-    expect($scheduledTask->getStatus())->null();
+    verify($scheduledTask->getStatus())->null();
     // set newsletter's status to sending
     $updatedNewsletter = $this->newslettersRepository->findOneById($newsletter->getId());
     $this->assertInstanceOf(NewsletterEntity::class, $updatedNewsletter);
@@ -785,7 +785,7 @@ class SchedulerTest extends \MailPoetTest {
     $scheduler = $this->getScheduler();
     $scheduler->process();
     $task = SendingTask::getByNewsletterId($newsletter->getId());
-    expect($task->status)->null();
+    verify($task->status)->null();
   }
 
   public function testItDeletesScheduledAutomaticEmailWhenUserDoesNotExist() {
@@ -844,7 +844,7 @@ class SchedulerTest extends \MailPoetTest {
     $scheduler = $this->getScheduler($this->subscribersFinder);
     $scheduler->process();
     $task = SendingTask::getByNewsletterId($newsletter->getId());
-    expect($task->status)->null();
+    verify($task->status)->null();
     // task should have 1 subscriber added from segment
     $subscribers = $task->subscribers()->findMany();
     expect($subscribers)->count(1);
@@ -871,7 +871,7 @@ class SchedulerTest extends \MailPoetTest {
     $scheduler = $this->getScheduler();
     $scheduler->process();
     $task = SendingTask::getByNewsletterId($newsletter->getId());
-    expect($task->status)->null();
+    verify($task->status)->null();
   }
 
   public function testItDeletesScheduledAutomationEmailWhenUserDoesNotExist() {
diff --git a/mailpoet/tests/integration/Cron/Workers/SendingQueue/SendingQueueTest.php b/mailpoet/tests/integration/Cron/Workers/SendingQueue/SendingQueueTest.php
index 3ba08d590a..7e1bd79163 100644
--- a/mailpoet/tests/integration/Cron/Workers/SendingQueue/SendingQueueTest.php
+++ b/mailpoet/tests/integration/Cron/Workers/SendingQueue/SendingQueueTest.php
@@ -420,12 +420,12 @@ class SendingQueueTest extends \MailPoetTest {
     $this->subscriber->setEngagementScoreUpdatedAt(Carbon::now()->subDays(5));
     $this->entityManager->flush();
     $this->entityManager->refresh($this->subscriber);
-    expect($this->subscriber->getLastSendingAt())->null();
+    verify($this->subscriber->getLastSendingAt())->null();
     expect($this->subscriber->getEngagementScoreUpdatedAt())->notNull();
     $sendingQueueWorker->process();
     $this->subscribersRepository->refresh($this->subscriber);
     expect($this->subscriber->getLastSendingAt())->notNull();
-    expect($this->subscriber->getEngagementScoreUpdatedAt())->null();
+    verify($this->subscriber->getEngagementScoreUpdatedAt())->null();
 
     // newsletter status is set to sent
     $updatedNewsletter = Newsletter::findOne($this->newsletter->id);
@@ -550,7 +550,7 @@ class SendingQueueTest extends \MailPoetTest {
         ]
       )
     );
-    expect($this->subscriber->getLastSendingAt())->null();
+    verify($this->subscriber->getLastSendingAt())->null();
     $sendingQueueWorker->process();
     $this->subscribersRepository->refresh($this->subscriber);
     expect($this->subscriber->getLastSendingAt())->notNull();
@@ -1018,7 +1018,7 @@ class SendingQueueTest extends \MailPoetTest {
     verify($sendingQueue->getCountTotal())->equals($expectSending ? 1 : 0);
     // Transactional emails shouldn't update last sending at
     $this->subscribersRepository->refresh($subscriber);
-    expect($subscriber->getLastSendingAt())->null();
+    verify($subscriber->getLastSendingAt())->null();
   }
 
   public function dataForTestItSendsTransactionalEmails(): array {
diff --git a/mailpoet/tests/integration/Cron/Workers/SendingQueue/Tasks/NewsletterTest.php b/mailpoet/tests/integration/Cron/Workers/SendingQueue/Tasks/NewsletterTest.php
index e637706650..2a90a09bc7 100644
--- a/mailpoet/tests/integration/Cron/Workers/SendingQueue/Tasks/NewsletterTest.php
+++ b/mailpoet/tests/integration/Cron/Workers/SendingQueue/Tasks/NewsletterTest.php
@@ -106,7 +106,7 @@ class NewsletterTest extends \MailPoetTest {
     $newsletterEntity->setStatus(NewsletterEntity::STATUS_DRAFT);
     $this->newslettersRepository->persist($newsletterEntity);
     $this->newslettersRepository->flush();
-    expect($this->newsletterTask->getNewsletterFromQueue($this->sendingTask))->null();
+    verify($this->newsletterTask->getNewsletterFromQueue($this->sendingTask))->null();
 
     // active or sending statuses return newsletter
     $newsletterEntity->setStatus(NewsletterEntity::STATUS_ACTIVE);
@@ -124,7 +124,7 @@ class NewsletterTest extends \MailPoetTest {
     $this->newsletter->setDeletedAt(new Carbon());
     $this->newslettersRepository->persist($this->newsletter);
     $this->newslettersRepository->flush();
-    expect($this->newsletterTask->getNewsletterFromQueue($this->sendingTask))->null();
+    verify($this->newsletterTask->getNewsletterFromQueue($this->sendingTask))->null();
   }
 
   public function testItDoesNotGetNewsletterWhenParentNewsletterStatusIsNotActiveOrSending() {
@@ -140,7 +140,7 @@ class NewsletterTest extends \MailPoetTest {
     $newsletterEntity->setParent($parentNewsletterEntity);
     $this->newslettersRepository->persist($newsletterEntity);
     $this->newslettersRepository->flush();
-    expect($this->newsletterTask->getNewsletterFromQueue($this->sendingTask))->null();
+    verify($this->newsletterTask->getNewsletterFromQueue($this->sendingTask))->null();
 
     // active or sending statuses return newsletter
     $parentNewsletterEntity->setStatus(NewsletterEntity::STATUS_ACTIVE);
@@ -163,7 +163,7 @@ class NewsletterTest extends \MailPoetTest {
     $newsletter->setParent($this->parentNewsletter);
     $this->newslettersRepository->persist($newsletter);
     $this->newslettersRepository->flush();
-    expect($this->newsletterTask->getNewsletterFromQueue($this->sendingTask))->null();
+    verify($this->newsletterTask->getNewsletterFromQueue($this->sendingTask))->null();
   }
 
   public function testItReturnsNewsletterObjectWhenRenderedNewsletterBodyExistsInTheQueue() {
@@ -202,7 +202,7 @@ class NewsletterTest extends \MailPoetTest {
     $newsletterTask->trackingEnabled = false;
     $newsletterTask->preProcessNewsletter($this->newsletter, $this->sendingTask);
     $link = $this->newsletterLinkRepository->findOneBy(['newsletter' => $this->newsletter->getId()]);
-    expect($link)->null();
+    verify($link)->null();
     $updatedQueue = SendingTask::getByNewsletterId($this->newsletter->getId());
     $renderedNewsletter = $updatedQueue->getNewsletterRenderedBody();
     expect($renderedNewsletter['html'])
@@ -231,7 +231,7 @@ class NewsletterTest extends \MailPoetTest {
     // newsletter is deleted.
     $this->entityManager->clear(); // needed while part of the code uses Paris models and part uses Doctrine
     $newsletter = $this->newslettersRepository->findOneById($this->newsletter->getId());
-    expect($newsletter)->null();
+    verify($newsletter)->null();
   }
 
   public function testItSavesNewsletterPosts() {
@@ -606,7 +606,7 @@ class NewsletterTest extends \MailPoetTest {
     $this->sendingQueuesRepository->flush();
     $newsletterTask = new NewsletterTask();
     $sendingQueueMeta = $sendingQueue->getMeta();
-    expect($sendingQueueMeta)->null();
+    verify($sendingQueueMeta)->null();
     verify($newsletterTask->preProcessNewsletter($this->newsletter, $this->sendingTask))->equals($this->newsletter);
     $this->entityManager->refresh($sendingQueue);
     $updatedMeta = $sendingQueue->getMeta();
diff --git a/mailpoet/tests/integration/Cron/Workers/StatsNotifications/NewsletterLinkRepositoryTest.php b/mailpoet/tests/integration/Cron/Workers/StatsNotifications/NewsletterLinkRepositoryTest.php
index 6fdfc5335e..c4b2299e19 100644
--- a/mailpoet/tests/integration/Cron/Workers/StatsNotifications/NewsletterLinkRepositoryTest.php
+++ b/mailpoet/tests/integration/Cron/Workers/StatsNotifications/NewsletterLinkRepositoryTest.php
@@ -61,6 +61,6 @@ class NewsletterLinkRepositoryTest extends \MailPoetTest {
     $this->entityManager->flush();
 
     $nonExistingTopLink = $repository->findTopLinkForNewsletter((int)$newsletter2->getId());
-    expect($nonExistingTopLink)->null();
+    verify($nonExistingTopLink)->null();
   }
 }
diff --git a/mailpoet/tests/integration/Cron/Workers/SubscribersLastEngagementTest.php b/mailpoet/tests/integration/Cron/Workers/SubscribersLastEngagementTest.php
index d424edbeda..a98e42a7ae 100644
--- a/mailpoet/tests/integration/Cron/Workers/SubscribersLastEngagementTest.php
+++ b/mailpoet/tests/integration/Cron/Workers/SubscribersLastEngagementTest.php
@@ -72,7 +72,7 @@ class SubscribersLastEngagementTest extends \MailPoetTest {
     $subscriber = $this->createSubscriber();
     $this->worker->processTaskStrategy(new ScheduledTaskEntity(), microtime(true));
     $this->entityManager->refresh($subscriber);
-    expect($subscriber->getLastEngagementAt())->null();
+    verify($subscriber->getLastEngagementAt())->null();
   }
 
   public function testItReturnsTrueWhenCompleted() {
diff --git a/mailpoet/tests/integration/Doctrine/Types/JsonTypesTest.php b/mailpoet/tests/integration/Doctrine/Types/JsonTypesTest.php
index 3b313eb5af..810d190fa7 100644
--- a/mailpoet/tests/integration/Doctrine/Types/JsonTypesTest.php
+++ b/mailpoet/tests/integration/Doctrine/Types/JsonTypesTest.php
@@ -91,7 +91,7 @@ class JsonTypesTest extends \MailPoetTest {
 
     $entity = $this->entityManager->find(JsonEntity::class, 1);
     $this->assertInstanceOf(JsonEntity::class, $entity); // PHPStan
-    expect($entity->getJsonData())->null();
+    verify($entity->getJsonData())->null();
     expect($entity->getJsonOrSerializedData())->same($this->testData);
   }
 
@@ -104,8 +104,8 @@ class JsonTypesTest extends \MailPoetTest {
 
     $savedData = $this->connection->executeQuery("SELECT * FROM $this->tableName")->fetchAssociative() ?: [];
     expect($savedData)->array();
-    expect($savedData['json_data'])->null();
-    expect($savedData['json_or_serialized_data'])->null();
+    verify($savedData['json_data'])->null();
+    verify($savedData['json_or_serialized_data'])->null();
   }
 
   public function testItLoadsNullData() {
@@ -120,8 +120,8 @@ class JsonTypesTest extends \MailPoetTest {
 
     $entity = $this->entityManager->find(JsonEntity::class, 1);
     $this->assertInstanceOf(JsonEntity::class, $entity); // PHPStan
-    expect($entity->getJsonData())->null();
-    expect($entity->getJsonOrSerializedData())->null();
+    verify($entity->getJsonData())->null();
+    verify($entity->getJsonOrSerializedData())->null();
   }
 
   public function testItLoadsEmptyStringAsNull() {
@@ -136,8 +136,8 @@ class JsonTypesTest extends \MailPoetTest {
 
     $entity = $this->entityManager->find(JsonEntity::class, 1);
     $this->assertInstanceOf(JsonEntity::class, $entity); // PHPStan
-    expect($entity->getJsonData())->null();
-    expect($entity->getJsonOrSerializedData())->null();
+    verify($entity->getJsonData())->null();
+    verify($entity->getJsonOrSerializedData())->null();
   }
 
   public function testItDoesNotSaveInvalidData() {
diff --git a/mailpoet/tests/integration/EmailEditor/Engine/Renderer/BlocksRegistryTest.php b/mailpoet/tests/integration/EmailEditor/Engine/Renderer/BlocksRegistryTest.php
index 54b3847ae8..f15e1fe1b5 100644
--- a/mailpoet/tests/integration/EmailEditor/Engine/Renderer/BlocksRegistryTest.php
+++ b/mailpoet/tests/integration/EmailEditor/Engine/Renderer/BlocksRegistryTest.php
@@ -18,7 +18,7 @@ class BlocksRegistryTest extends \MailPoetTest {
 
   public function testItReturnsNullForUnknownRenderer() {
     $storedRenderer = $this->registry->getBlockRenderer('test');
-    expect($storedRenderer)->null();
+    verify($storedRenderer)->null();
   }
 
   public function testItStoresAddedRenderer() {
diff --git a/mailpoet/tests/integration/Entities/NewsletterEntityTest.php b/mailpoet/tests/integration/Entities/NewsletterEntityTest.php
index 74c0329c01..ebfb42e414 100644
--- a/mailpoet/tests/integration/Entities/NewsletterEntityTest.php
+++ b/mailpoet/tests/integration/Entities/NewsletterEntityTest.php
@@ -76,7 +76,7 @@ class NewsletterEntityTest extends \MailPoetTest {
 
     expect($newsletterOptionField)->notNull();
     verify($newsletterOption->getValue())->equals($optionValue);
-    expect($newsletter->getOption(NewsletterOptionFieldEntity::NAME_SEGMENT))->null();
+    verify($newsletter->getOption(NewsletterOptionFieldEntity::NAME_SEGMENT))->null();
   }
 
   public function testItPausesTaskWhenPausingNewsletter() {
@@ -184,7 +184,7 @@ class NewsletterEntityTest extends \MailPoetTest {
   public function testItCanRetrieveFilterSegmentIdOption(): void {
     $optionField = (new NewsletterOptionField())->findOrCreate(NewsletterOptionFieldEntity::NAME_FILTER_SEGMENT_ID);
     $newsletter = $this->createNewsletter();
-    expect($newsletter->getFilterSegmentId())->null();
+    verify($newsletter->getFilterSegmentId())->null();
 
     $newsletterOption = new NewsletterOptionEntity($newsletter, $optionField);
     $newsletterOption->setValue('2');
@@ -199,7 +199,7 @@ class NewsletterEntityTest extends \MailPoetTest {
   public function testItInheritsFilterSegmentIdFromParent(): void {
     $optionField = (new NewsletterOptionField())->findOrCreate(NewsletterOptionFieldEntity::NAME_FILTER_SEGMENT_ID, NewsletterEntity::TYPE_NOTIFICATION);
     $notificationNewsletter = $this->createNewsletter(NewsletterEntity::TYPE_NOTIFICATION);
-    expect($notificationNewsletter->getFilterSegmentId())->null();
+    verify($notificationNewsletter->getFilterSegmentId())->null();
 
     $newsletterOption = new NewsletterOptionEntity($notificationNewsletter, $optionField);
     $newsletterOption->setValue('2');
@@ -211,7 +211,7 @@ class NewsletterEntityTest extends \MailPoetTest {
     verify($notificationNewsletter->getFilterSegmentId())->equals(2);
 
     $notificationHistoryNewsletter = $this->createNewsletter(NewsletterEntity::TYPE_NOTIFICATION_HISTORY);
-    expect($notificationHistoryNewsletter->getFilterSegmentId())->null();
+    verify($notificationHistoryNewsletter->getFilterSegmentId())->null();
 
     $notificationHistoryNewsletter->setParent($notificationNewsletter);
     $this->entityManager->persist($notificationHistoryNewsletter);
diff --git a/mailpoet/tests/integration/Form/FormsRepositoryTest.php b/mailpoet/tests/integration/Form/FormsRepositoryTest.php
index f7cf608b30..343fc385c1 100644
--- a/mailpoet/tests/integration/Form/FormsRepositoryTest.php
+++ b/mailpoet/tests/integration/Form/FormsRepositoryTest.php
@@ -17,12 +17,12 @@ class FormsRepositoryTest extends \MailPoetTest {
     $form = $this->createForm('Form 1');
     expect($this->repository->findOneById($form->getId()))->isInstanceOf(FormEntity::class);
     $this->repository->delete($form);
-    expect($form->getId())->null();
+    verify($form->getId())->null();
   }
 
   public function testItCanTrashForm() {
     $form = $this->createForm('Form 1');
-    expect($form->getDeletedAt())->null();
+    verify($form->getDeletedAt())->null();
     $this->repository->trash($form);
     expect($form->getDeletedAt())->notNull();
   }
@@ -32,7 +32,7 @@ class FormsRepositoryTest extends \MailPoetTest {
     $this->repository->trash($form);
     expect($form->getDeletedAt())->notNull();
     $this->repository->restore($form);
-    expect($form->getDeletedAt())->null();
+    verify($form->getDeletedAt())->null();
   }
 
   private function createForm(string $name): FormEntity {
diff --git a/mailpoet/tests/integration/Homepage/HomepageDataControllerTest.php b/mailpoet/tests/integration/Homepage/HomepageDataControllerTest.php
index 642fbd5998..b5e47f62cf 100644
--- a/mailpoet/tests/integration/Homepage/HomepageDataControllerTest.php
+++ b/mailpoet/tests/integration/Homepage/HomepageDataControllerTest.php
@@ -61,7 +61,7 @@ class HomepageDataControllerTest extends \MailPoetTest {
     $settings = $this->diContainer->get(SettingsController::class);
     $settings->set('homepage.task_list_dismissed', true);
     $data = $this->homepageDataController->getPageData();
-    expect($data['taskListStatus'])->null();
+    verify($data['taskListStatus'])->null();
   }
 
   public function testItFetchesSubscribersAddedTaskListStatus(): void {
diff --git a/mailpoet/tests/integration/Mailer/MailerLogTest.php b/mailpoet/tests/integration/Mailer/MailerLogTest.php
index f0487e299c..5baca45c81 100644
--- a/mailpoet/tests/integration/Mailer/MailerLogTest.php
+++ b/mailpoet/tests/integration/Mailer/MailerLogTest.php
@@ -41,7 +41,7 @@ class MailerLogTest extends \MailPoetTest {
     $mailerConfig = $settings->get(Mailer::MAILER_CONFIG_SETTING_NAME);
     $mailerConfig['method'] = Mailer::METHOD_MAILPOET;
     $settings->set(Mailer::MAILER_CONFIG_SETTING_NAME, $mailerConfig);
-    expect(MailerLog::incrementSentCount())->null();
+    verify(MailerLog::incrementSentCount())->null();
     verify(MailerLog::sentSince())->equals($expectedCount);
   }
 
@@ -53,9 +53,9 @@ class MailerLogTest extends \MailPoetTest {
     $mailerLog = MailerLog::getMailerLog();
     $mailerLog['error'] = ['operation' => 'send', 'error_message' => ''];
     $this->settings->set(MailerLog::SETTING_NAME, $mailerLog);
-    expect(MailerLog::incrementSentCount())->null();
+    verify(MailerLog::incrementSentCount())->null();
     $mailerLog = MailerLog::getMailerLog();
-    expect($mailerLog['error'])->null();
+    verify($mailerLog['error'])->null();
   }
 
   public function testItCreatesMailer() {
@@ -191,7 +191,7 @@ class MailerLogTest extends \MailPoetTest {
     // status is reset when sending is resumed
     MailerLog::resumeSending();
     $mailerLog = MailerLog::getMailerLog();
-    expect($mailerLog['status'])->null();
+    verify($mailerLog['status'])->null();
   }
 
   public function testItPausesSending() {
@@ -204,16 +204,16 @@ class MailerLogTest extends \MailPoetTest {
     MailerLog::pauseSending($mailerLog);
     $mailerLog = MailerLog::getMailerLog();
     verify($mailerLog['status'])->equals(MailerLog::STATUS_PAUSED);
-    expect($mailerLog['retry_attempt'])->null();
-    expect($mailerLog['retry_at'])->null();
+    verify($mailerLog['retry_attempt'])->null();
+    verify($mailerLog['retry_at'])->null();
   }
 
   public function testItProcessesSendingError() {
     // retry-related mailer values should be null
     $mailerLog = MailerLog::getMailerLog();
-    expect($mailerLog['retry_attempt'])->null();
-    expect($mailerLog['retry_at'])->null();
-    expect($mailerLog['error'])->null();
+    verify($mailerLog['retry_attempt'])->null();
+    verify($mailerLog['retry_at'])->null();
+    verify($mailerLog['error'])->null();
     // retry attempt should be incremented, error logged, retry attempt scheduled
     $this->expectException('\Exception');
     MailerLog::processError($operation = 'send', $error = 'email rejected');
@@ -230,9 +230,9 @@ class MailerLogTest extends \MailPoetTest {
 
   public function testItProcessesNonBlockingSendingError() {
     $mailerLog = MailerLog::getMailerLog();
-    expect($mailerLog['retry_attempt'])->null();
-    expect($mailerLog['retry_at'])->null();
-    expect($mailerLog['error'])->null();
+    verify($mailerLog['retry_attempt'])->null();
+    verify($mailerLog['retry_at'])->null();
+    verify($mailerLog['error'])->null();
     $this->expectException('\Exception');
     MailerLog::processNonBlockingError($operation = 'send', $error = 'email rejected');
     $mailerLog = MailerLog::getMailerLog();
@@ -248,7 +248,7 @@ class MailerLogTest extends \MailPoetTest {
 
   public function testItPausesSendingAfterProcessingSendingError() {
     $mailerLog = MailerLog::getMailerLog();
-    expect($mailerLog['error'])->null();
+    verify($mailerLog['error'])->null();
     $error = null;
     try {
       MailerLog::processError($operation = 'send', $error = 'email rejected - sending paused', $errorCode = null, $pauseSending = true);
@@ -257,8 +257,8 @@ class MailerLogTest extends \MailPoetTest {
       verify($e->getMessage())->equals('Sending has been paused.');
     }
     $mailerLog = MailerLog::getMailerLog();
-    expect($mailerLog['retry_attempt'])->null();
-    expect($mailerLog['retry_at'])->null();
+    verify($mailerLog['retry_attempt'])->null();
+    verify($mailerLog['retry_at'])->null();
     verify($mailerLog['status'])->equals(MailerLog::STATUS_PAUSED);
     verify($mailerLog['error'])->equals(
       [
@@ -273,8 +273,8 @@ class MailerLogTest extends \MailPoetTest {
 
   public function testItProcessesTransactionalEmailSendingError() {
     $mailerLog = MailerLog::getMailerLog();
-    expect($mailerLog['transactional_email_last_error_at'])->null();
-    expect($mailerLog['transactional_email_error_count'])->null();
+    verify($mailerLog['transactional_email_last_error_at'])->null();
+    verify($mailerLog['transactional_email_error_count'])->null();
     MailerLog::processTransactionalEmailError(MailerError::OPERATION_SEND, 'email rejected');
     $mailerLog = MailerLog::getMailerLog();
     verify($mailerLog['transactional_email_last_error_at'])->equals(time(), 1);
@@ -319,8 +319,8 @@ class MailerLogTest extends \MailPoetTest {
     MailerLog::updateMailerLog($mailerLog);
     MailerLog::processTransactionalEmailError(MailerError::OPERATION_SEND, 'email rejected');
     $mailerLog = MailerLog::getMailerLog();
-    expect($mailerLog['transactional_email_last_error_at'])->null();
-    expect($mailerLog['transactional_email_error_count'])->null();
+    verify($mailerLog['transactional_email_last_error_at'])->null();
+    verify($mailerLog['transactional_email_error_count'])->null();
     verify(MailerLog::isSendingPaused())->true();
     $logs = $this->entityManager->getRepository(LogEntity::class)->findAll();
     $this->assertInstanceOf(LogEntity::class, $logs[0]);
@@ -408,7 +408,7 @@ class MailerLogTest extends \MailPoetTest {
     $mailerLog = MailerLog::createMailerLog();
     $mailerLog['retry_attempt'] = 2;
     // allow less than 3 attempts
-    expect(MailerLog::enforceExecutionRequirements($mailerLog))->null();
+    verify(MailerLog::enforceExecutionRequirements($mailerLog))->null();
     // pase sending and throw exception when more than 3 attempts
     $mailerLog['retry_attempt'] = MailerLog::RETRY_ATTEMPTS_LIMIT;
     try {
@@ -434,11 +434,11 @@ class MailerLogTest extends \MailPoetTest {
     ];
     $mailerLog['status'] = 'status';
     $mailerLog = MailerLog::clearSendingErrorLog($mailerLog);
-    expect($mailerLog['retry_attempt'])->null();
-    expect($mailerLog['retry_at'])->null();
-    expect($mailerLog['error'])->null();
-    expect($mailerLog['transactional_email_last_error_at'])->null();
-    expect($mailerLog['transactional_email_error_count'])->null();
+    verify($mailerLog['retry_attempt'])->null();
+    verify($mailerLog['retry_at'])->null();
+    verify($mailerLog['error'])->null();
+    verify($mailerLog['transactional_email_last_error_at'])->null();
+    verify($mailerLog['transactional_email_error_count'])->null();
     verify($mailerLog['status'])->equals('status');
   }
 
diff --git a/mailpoet/tests/integration/Models/NewsletterTest.php b/mailpoet/tests/integration/Models/NewsletterTest.php
index 380990a0db..aa42b2ffbf 100644
--- a/mailpoet/tests/integration/Models/NewsletterTest.php
+++ b/mailpoet/tests/integration/Models/NewsletterTest.php
@@ -213,7 +213,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($this->newsletter->deletedAt)->notNull();
     $this->newsletter->restore();
     $this->newsletter = $this->reloadNewsletter($this->newsletter);
-    expect($this->newsletter->deletedAt)->null();
+    verify($this->newsletter->deletedAt)->null();
     verify($this->newsletter->status)->equals(Newsletter::STATUS_SENT);
   }
 
diff --git a/mailpoet/tests/integration/Models/SubscriberTest.php b/mailpoet/tests/integration/Models/SubscriberTest.php
index 379d9ec5d8..bd06eae3ba 100644
--- a/mailpoet/tests/integration/Models/SubscriberTest.php
+++ b/mailpoet/tests/integration/Models/SubscriberTest.php
@@ -133,7 +133,7 @@ class SubscriberTest extends \MailPoetTest {
     $subscriber->save();
     $subscriberUpdated = Subscriber::where('email', $this->testData['email'])
       ->findOne();
-    expect($subscriberUpdated->lastSubscribedAt)->null();
+    verify($subscriberUpdated->lastSubscribedAt)->null();
 
     // Change to subscribed updates last_updated_at
     $subscriber->status = Subscriber::STATUS_SUBSCRIBED;
diff --git a/mailpoet/tests/integration/Newsletter/NewsletterRepositoryTest.php b/mailpoet/tests/integration/Newsletter/NewsletterRepositoryTest.php
index eb01e8717e..8b9a6790e1 100644
--- a/mailpoet/tests/integration/Newsletter/NewsletterRepositoryTest.php
+++ b/mailpoet/tests/integration/Newsletter/NewsletterRepositoryTest.php
@@ -93,8 +93,8 @@ class NewsletterRepositoryTest extends \MailPoetTest {
     $this->entityManager->refresh($notification);
 
     // Should trash the newsletters
-    expect($standardNewsletter->getDeletedAt())->null();
-    expect($notification->getDeletedAt())->null();
+    verify($standardNewsletter->getDeletedAt())->null();
+    verify($notification->getDeletedAt())->null();
     verify($standardNewsletter->getStatus())->equals(NewsletterEntity::STATUS_SENDING);
     verify($notification->getStatus())->equals(NewsletterEntity::STATUS_ACTIVE);
 
@@ -102,25 +102,25 @@ class NewsletterRepositoryTest extends \MailPoetTest {
     $standardQueue = $standardNewsletter->getLatestQueue();
     $this->assertInstanceOf(SendingQueueEntity::class, $standardQueue);
     $this->entityManager->refresh($standardQueue);
-    expect($standardQueue->getDeletedAt())->null();
+    verify($standardQueue->getDeletedAt())->null();
     $scheduledTask = $standardQueue->getTask();
     $this->assertInstanceOf(ScheduledTaskEntity::class, $scheduledTask);
     $this->entityManager->refresh($scheduledTask);
-    expect($scheduledTask->getDeletedAt())->null();
+    verify($scheduledTask->getDeletedAt())->null();
     // Pause sending tasks which were in progress
     verify($scheduledTask->getStatus())->equals(ScheduledTaskEntity::STATUS_PAUSED);
 
     // Should restore children + task + queue
     $this->entityManager->refresh($notificationHistory);
-    expect($notificationHistory->getDeletedAt())->null();
+    verify($notificationHistory->getDeletedAt())->null();
     $notificationHistoryQueue = $notificationHistory->getLatestQueue();
     $this->assertInstanceOf(SendingQueueEntity::class, $notificationHistoryQueue);
     $this->entityManager->refresh($notificationHistoryQueue);
-    expect($notificationHistoryQueue->getDeletedAt())->null();
+    verify($notificationHistoryQueue->getDeletedAt())->null();
     $scheduledTask = $notificationHistoryQueue->getTask();
     $this->assertInstanceOf(ScheduledTaskEntity::class, $scheduledTask);
     $this->entityManager->refresh($scheduledTask);
-    expect($scheduledTask->getDeletedAt())->null();
+    verify($scheduledTask->getDeletedAt())->null();
     verify($scheduledTask->getStatus())->equals(ScheduledTaskEntity::STATUS_SCHEDULED);
   }
 
@@ -172,51 +172,51 @@ class NewsletterRepositoryTest extends \MailPoetTest {
 
     // Check they were all deleted
     // Newsletters
-    expect($this->repository->findOneById($standardNewsletter->getId()))->null();
-    expect($this->repository->findOneById($notification->getId()))->null();
-    expect($this->repository->findOneById($notificationHistory->getId()))->null();
+    verify($this->repository->findOneById($standardNewsletter->getId()))->null();
+    verify($this->repository->findOneById($notification->getId()))->null();
+    verify($this->repository->findOneById($notificationHistory->getId()))->null();
 
     // Sending queues
-    expect($this->entityManager->find(SendingQueueEntity::class, $standardQueue->getId()))->null();
-    expect($this->entityManager->find(SendingQueueEntity::class, $notificationHistoryQueue->getId()))->null();
+    verify($this->entityManager->find(SendingQueueEntity::class, $standardQueue->getId()))->null();
+    verify($this->entityManager->find(SendingQueueEntity::class, $notificationHistoryQueue->getId()))->null();
 
     // Scheduled tasks subscribers
-    expect($this->taskSubscribersRepository->findOneBy(['task' => $standardScheduledTaks]))->null();
-    expect($this->taskSubscribersRepository->findOneBy(['task' => $notificationHistoryScheduledTask]))->null();
+    verify($this->taskSubscribersRepository->findOneBy(['task' => $standardScheduledTaks]))->null();
+    verify($this->taskSubscribersRepository->findOneBy(['task' => $notificationHistoryScheduledTask]))->null();
 
     // Scheduled tasks
-    expect($this->entityManager->find(ScheduledTaskEntity::class, $standardScheduledTaks->getId()))->null();
-    expect($this->entityManager->find(ScheduledTaskEntity::class, $notificationHistoryScheduledTask->getId()))->null();
+    verify($this->entityManager->find(ScheduledTaskEntity::class, $standardScheduledTaks->getId()))->null();
+    verify($this->entityManager->find(ScheduledTaskEntity::class, $notificationHistoryScheduledTask->getId()))->null();
 
     // Newsletter segments
-    expect($this->entityManager->find(NewsletterSegmentEntity::class, $standardSegment->getId()))->null();
-    expect($this->entityManager->find(NewsletterSegmentEntity::class, $notificationHistorySegment->getId()))->null();
+    verify($this->entityManager->find(NewsletterSegmentEntity::class, $standardSegment->getId()))->null();
+    verify($this->entityManager->find(NewsletterSegmentEntity::class, $notificationHistorySegment->getId()))->null();
 
     // Newsletter stats notifications
-    expect($this->entityManager->find(StatsNotificationEntity::class, $standardStatsNotificationScheduledTask->getId()))->null();
-    expect($this->entityManager->find(StatsNotificationEntity::class, $notificationHistoryStatsNotification->getId()))->null();
+    verify($this->entityManager->find(StatsNotificationEntity::class, $standardStatsNotificationScheduledTask->getId()))->null();
+    verify($this->entityManager->find(StatsNotificationEntity::class, $notificationHistoryStatsNotification->getId()))->null();
 
     // Newsletter stats notifications scheduled tasks
-    expect($this->entityManager->find(ScheduledTaskEntity::class, $standardStatsNotificationScheduledTask->getId()))->null();
-    expect($this->entityManager->find(ScheduledTaskEntity::class, $notificationHistoryStatsNotificationScheduledTask->getId()))->null();
+    verify($this->entityManager->find(ScheduledTaskEntity::class, $standardStatsNotificationScheduledTask->getId()))->null();
+    verify($this->entityManager->find(ScheduledTaskEntity::class, $notificationHistoryStatsNotificationScheduledTask->getId()))->null();
 
     // Newsletter links
-    expect($this->entityManager->find(NewsletterLinkEntity::class, $standardLink->getId()))->null();
-    expect($this->entityManager->find(NewsletterLinkEntity::class, $notificationHistoryLink->getId()))->null();
+    verify($this->entityManager->find(NewsletterLinkEntity::class, $standardLink->getId()))->null();
+    verify($this->entityManager->find(NewsletterLinkEntity::class, $notificationHistoryLink->getId()))->null();
 
     // Option fields values
-    expect($this->entityManager->find(NewsletterOptionEntity::class, $optionValue->getId()))->null();
+    verify($this->entityManager->find(NewsletterOptionEntity::class, $optionValue->getId()))->null();
 
     // Newsletter post
-    expect($this->entityManager->find(NewsletterPostEntity::class, $newsletterPost->getId()))->null();
+    verify($this->entityManager->find(NewsletterPostEntity::class, $newsletterPost->getId()))->null();
 
     // Statistics data
-    expect($this->entityManager->find(StatisticsNewsletterEntity::class, $statisticsNewsletter->getId()))->null();
-    expect($this->entityManager->find(StatisticsOpenEntity::class, $statisticsOpen->getId()))->null();
-    expect($this->entityManager->find(StatisticsClickEntity::class, $statisticsClick->getId()))->null();
+    verify($this->entityManager->find(StatisticsNewsletterEntity::class, $statisticsNewsletter->getId()))->null();
+    verify($this->entityManager->find(StatisticsOpenEntity::class, $statisticsOpen->getId()))->null();
+    verify($this->entityManager->find(StatisticsClickEntity::class, $statisticsClick->getId()))->null();
     $statisticsPurchase = $this->entityManager->find(StatisticsWooCommercePurchaseEntity::class, $statisticsPurchase->getId());
     $this->assertNotNull($statisticsPurchase);
-    expect($statisticsPurchase->getNewsletter())->null();
+    verify($statisticsPurchase->getNewsletter())->null();
   }
 
   public function testItDeletesMultipleNewslettersWithPurchaseStatsAndKeepsStats() {
@@ -232,16 +232,16 @@ class NewsletterRepositoryTest extends \MailPoetTest {
     $this->entityManager->clear();
 
     // Check Newsletters were deleted
-    expect($this->repository->findOneById($standardNewsletter1->getId()))->null();
-    expect($this->repository->findOneById($standardNewsletter2->getId()))->null();
+    verify($this->repository->findOneById($standardNewsletter1->getId()))->null();
+    verify($this->repository->findOneById($standardNewsletter2->getId()))->null();
 
     // Check purchase stats were not deleted
     $statisticsPurchase1 = $this->entityManager->find(StatisticsWooCommercePurchaseEntity::class, $statisticsPurchase1->getId());
     $statisticsPurchase2 = $this->entityManager->find(StatisticsWooCommercePurchaseEntity::class, $statisticsPurchase2->getId());
     $this->assertNotNull($statisticsPurchase1);
-    expect($statisticsPurchase1->getNewsletter())->null();
+    verify($statisticsPurchase1->getNewsletter())->null();
     $this->assertNotNull($statisticsPurchase2);
-    expect($statisticsPurchase2->getNewsletter())->null();
+    verify($statisticsPurchase2->getNewsletter())->null();
   }
 
   public function testItDeletesWpPostsBulkDelete() {
@@ -260,8 +260,8 @@ class NewsletterRepositoryTest extends \MailPoetTest {
     $this->entityManager->clear();
 
     $this->repository->bulkDelete([$newsletter1->getId(), $newsletter2->getId(), $newsletter3->getId()]);
-    expect($this->wp->getPost($post1Id))->null();
-    expect($this->wp->getPost($post2Id))->null();
+    verify($this->wp->getPost($post1Id))->null();
+    verify($this->wp->getPost($post2Id))->null();
   }
 
   public function testItGetsArchiveNewslettersForSegments() {
diff --git a/mailpoet/tests/integration/Newsletter/NewsletterSaveControllerTest.php b/mailpoet/tests/integration/Newsletter/NewsletterSaveControllerTest.php
index f2329de715..65d320bcd6 100644
--- a/mailpoet/tests/integration/Newsletter/NewsletterSaveControllerTest.php
+++ b/mailpoet/tests/integration/Newsletter/NewsletterSaveControllerTest.php
@@ -72,8 +72,8 @@ class NewsletterSaveControllerTest extends \MailPoetTest {
     $newsletter = $this->saveController->save($newsletterData);
     $updatedQueue = $newsletter->getLatestQueue();
     $this->assertInstanceOf(SendingQueueEntity::class, $updatedQueue); // PHPStan
-    expect($updatedQueue->getNewsletterRenderedSubject())->null();
-    expect($updatedQueue->getNewsletterRenderedBody())->null();
+    verify($updatedQueue->getNewsletterRenderedSubject())->null();
+    verify($updatedQueue->getNewsletterRenderedBody())->null();
   }
 
   public function testItCanRerenderQueueUponSave() {
@@ -174,7 +174,7 @@ class NewsletterSaveControllerTest extends \MailPoetTest {
     $this->assertInstanceOf(NewsletterOptionEntity::class, $scheduleOption); // PHPStan
 
     verify($task1->getScheduledAt())->equals($this->scheduler->getNextRunDate($scheduleOption->getValue()));
-    expect($task2->getScheduledAt())->null();
+    verify($task2->getScheduledAt())->null();
   }
 
   public function testItCanModifySegmentsOfExistingNewsletter() {
@@ -244,8 +244,8 @@ class NewsletterSaveControllerTest extends \MailPoetTest {
 
     $newsletter = $this->saveController->save($newsletterData);
     verify($newsletter->getStatus())->equals(NewsletterEntity::STATUS_DRAFT);
-    expect($newsletter->getLatestQueue())->null();
-    expect($this->diContainer->get(SendingQueuesRepository::class)->findOneById($queueId))->null();
+    verify($newsletter->getLatestQueue())->null();
+    verify($this->diContainer->get(SendingQueuesRepository::class)->findOneById($queueId))->null();
   }
 
   public function testItSavesDefaultSenderIfNeeded() {
@@ -280,7 +280,7 @@ class NewsletterSaveControllerTest extends \MailPoetTest {
     ];
 
     $this->saveController->save($data);
-    expect($settings->get('sender'))->null();
+    verify($settings->get('sender'))->null();
   }
 
   public function testItDoesntOverrideDefaultSender() {
diff --git a/mailpoet/tests/integration/Newsletter/NewsletterValidatorTest.php b/mailpoet/tests/integration/Newsletter/NewsletterValidatorTest.php
index 13e3c3c683..31623a6831 100644
--- a/mailpoet/tests/integration/Newsletter/NewsletterValidatorTest.php
+++ b/mailpoet/tests/integration/Newsletter/NewsletterValidatorTest.php
@@ -20,7 +20,7 @@ class NewsletterValidatorTest extends \MailPoetTest {
   public function testUnsubscribeFooterIsNotRequiredIfNotUsingMSS() {
       $newsletter = (new Newsletter())->loadBodyFrom('newsletterWithTextNoFooter.json')->create();
       $validationError = $this->newsletterValidator->validate($newsletter);
-      expect($validationError)->null();
+      verify($validationError)->null();
   }
 
   public function testUnsubscribeFooterRequiredIfUsingMSS() {
@@ -51,7 +51,7 @@ class NewsletterValidatorTest extends \MailPoetTest {
       ],
     ]]])->create();
     $validationError = $this->newsletterValidator->validate($newsletter);
-    expect($validationError)->null();
+    verify($validationError)->null();
   }
 
   public function testItRequiresReengagementShortcodes() {
@@ -72,7 +72,7 @@ class NewsletterValidatorTest extends \MailPoetTest {
       ],
     ])->create();
     $validationError = $this->newsletterValidator->validate($newsletter);
-    expect($validationError)->null();
+    verify($validationError)->null();
   }
 
   public function testItRequiresTrackingForReengagementEmails() {
@@ -102,6 +102,6 @@ class NewsletterValidatorTest extends \MailPoetTest {
   public function testAlcEmailPassesWithAlcBlock() {
     $newsletter = (new Newsletter())->loadBodyFrom('newsletterWithALC.json')->withPostNotificationsType()->create();
     $validationError = $this->newsletterValidator->validate($newsletter);
-    expect($validationError)->null();
+    verify($validationError)->null();
   }
 }
diff --git a/mailpoet/tests/integration/Newsletter/RendererTest.php b/mailpoet/tests/integration/Newsletter/RendererTest.php
index d501006c5c..52a1e58dab 100644
--- a/mailpoet/tests/integration/Newsletter/RendererTest.php
+++ b/mailpoet/tests/integration/Newsletter/RendererTest.php
@@ -477,7 +477,7 @@ class RendererTest extends \MailPoetTest {
     $newsletter = (array)$this->newsletter->getBody();
     $template = $newsletter['content']['blocks'][0]['blocks'][0]['blocks'][4];
     $DOM = $this->dOMParser->parseStr((new Spacer)->render($template));
-    expect($DOM('tr > td.mailpoet_spacer', 0)->attr('bgcolor'))->null();
+    verify($DOM('tr > td.mailpoet_spacer', 0)->attr('bgcolor'))->null();
     $template['styles']['block']['backgroundColor'] = '#ffff';
     $DOM = $this->dOMParser->parseStr((new Spacer)->render($template));
     verify($DOM('tr > td.mailpoet_spacer', 0)->attr('bgcolor'))
diff --git a/mailpoet/tests/integration/Newsletter/Scheduler/PostNotificationTest.php b/mailpoet/tests/integration/Newsletter/Scheduler/PostNotificationTest.php
index b078dc2c86..1051980507 100644
--- a/mailpoet/tests/integration/Newsletter/Scheduler/PostNotificationTest.php
+++ b/mailpoet/tests/integration/Newsletter/Scheduler/PostNotificationTest.php
@@ -135,7 +135,7 @@ class PostNotificationTest extends \MailPoetTest {
     // queue is not created when notification was already sent for the post
     $this->postNotificationScheduler->schedulePostNotification($postId);
     $queue = $this->sendingQueuesRepository->findOneBy(['newsletter' => $newsletter]);
-    expect($queue)->null();
+    verify($queue)->null();
   }
 
   public function testItSchedulesPostNotification() {
@@ -374,7 +374,7 @@ class PostNotificationTest extends \MailPoetTest {
     wp_insert_post($postData);
 
     $queue = $this->sendingQueuesRepository->findOneBy(['newsletter' => $newsletter]);
-    expect($queue)->null();
+    verify($queue)->null();
 
     $this->_removePostNotificationHooks();
     register_post_type('post', ['exclude_from_search' => false]);
@@ -420,7 +420,7 @@ class PostNotificationTest extends \MailPoetTest {
     wp_insert_post($postData);
 
     $queue = $this->sendingQueuesRepository->findOneBy(['newsletter' => $newsletter]);
-    expect($queue)->null();
+    verify($queue)->null();
   }
 
   public function _removePostNotificationHooks() {
diff --git a/mailpoet/tests/integration/Newsletter/Scheduler/WelcomeTest.php b/mailpoet/tests/integration/Newsletter/Scheduler/WelcomeTest.php
index 062bc76384..9b35304075 100644
--- a/mailpoet/tests/integration/Newsletter/Scheduler/WelcomeTest.php
+++ b/mailpoet/tests/integration/Newsletter/Scheduler/WelcomeTest.php
@@ -185,7 +185,7 @@ class WelcomeTest extends \MailPoetTest {
 
     // queue is not created
     $queue = $this->newsletter->getLatestQueue();
-    expect($queue)->null();
+    verify($queue)->null();
   }
 
   public function testItSchedulesSubscriberWelcomeNotification() {
@@ -300,7 +300,7 @@ class WelcomeTest extends \MailPoetTest {
 
     // queue is not created
     $queue = $newsletter->getLatestQueue();
-    expect($queue)->null();
+    verify($queue)->null();
   }
 
   public function testItDoesNotScheduleWPUserWelcomeNotificationWhenUserRoleDoesNotMatch() {
@@ -320,7 +320,7 @@ class WelcomeTest extends \MailPoetTest {
 
     // queue is not created
     $queue = $newsletter->getLatestQueue();
-    expect($queue)->null();
+    verify($queue)->null();
   }
 
   public function testItDoesNotSchedulesWPUserWelcomeNotificationWhenSubscriberIsInTrash() {
@@ -342,7 +342,7 @@ class WelcomeTest extends \MailPoetTest {
     );
     // queue is created and scheduled for delivery one day later
     $queue = $newsletter->getLatestQueue();
-    expect($queue)->null();
+    verify($queue)->null();
   }
 
   public function testItDoesNotSchedulesWPUserWelcomeNotificationWhenWpSegmentIsInTrash() {
@@ -363,7 +363,7 @@ class WelcomeTest extends \MailPoetTest {
     );
     // queue is created and scheduled for delivery one day later
     $queue = $newsletter->getLatestQueue();
-    expect($queue)->null();
+    verify($queue)->null();
   }
 
   public function testItSchedulesWPUserWelcomeNotificationWhenUserRolesMatches() {
diff --git a/mailpoet/tests/integration/Newsletter/Sending/SendingQueuesRepositoryTest.php b/mailpoet/tests/integration/Newsletter/Sending/SendingQueuesRepositoryTest.php
index cbc1cf0d2c..3258402642 100644
--- a/mailpoet/tests/integration/Newsletter/Sending/SendingQueuesRepositoryTest.php
+++ b/mailpoet/tests/integration/Newsletter/Sending/SendingQueuesRepositoryTest.php
@@ -87,7 +87,7 @@ class SendingQueuesRepositoryTest extends \MailPoetTest {
     $this->repository->resume($queue);
     $this->entityManager->refresh($task);
 
-    expect($task->getStatus())->null();
+    verify($task->getStatus())->null();
     verify($newsletter->getStatus())->equals(NewsletterEntity::STATUS_SENDING);
   }
 
diff --git a/mailpoet/tests/integration/Newsletter/ShortcodesTest.php b/mailpoet/tests/integration/Newsletter/ShortcodesTest.php
index 2fd39b1200..591bf08e58 100644
--- a/mailpoet/tests/integration/Newsletter/ShortcodesTest.php
+++ b/mailpoet/tests/integration/Newsletter/ShortcodesTest.php
@@ -391,7 +391,7 @@ class ShortcodesTest extends \MailPoetTest {
     $shortcodesObject->setWpUserPreview(false);
     $shortcode = '[link:shortcode arg1="val1" arg2="val2"]'; // WP style arguments
     $result = $shortcodesObject->process([$shortcode]);
-    expect($result[0])->null();
+    verify($result[0])->null();
     remove_all_filters('mailpoet_newsletter_shortcode_link');
     add_filter('mailpoet_newsletter_shortcode_link', function($shortcode, $newsletter, $subscriber, $queue, $arguments) {
       expect($arguments)->count(2);
diff --git a/mailpoet/tests/integration/NewsletterTemplates/ThumbnailSaverTest.php b/mailpoet/tests/integration/NewsletterTemplates/ThumbnailSaverTest.php
index ab6048b924..e47242be4e 100644
--- a/mailpoet/tests/integration/NewsletterTemplates/ThumbnailSaverTest.php
+++ b/mailpoet/tests/integration/NewsletterTemplates/ThumbnailSaverTest.php
@@ -50,7 +50,7 @@ class ThumbnailSaverTest extends \MailPoetTest {
     $template = $this->thumbnailSaver->ensureTemplateThumbnailFile($template);
     $thumbnailUrl = $template->getThumbnail();
     // Base url was updated back to initial value
-    expect($thumbnailUrl)->null();
+    verify($thumbnailUrl)->null();
   }
 
   private function createTemplate(): NewsletterTemplateEntity {
diff --git a/mailpoet/tests/integration/Router/RouterTest.php b/mailpoet/tests/integration/Router/RouterTest.php
index 146e1269f8..29b1279eb2 100644
--- a/mailpoet/tests/integration/Router/RouterTest.php
+++ b/mailpoet/tests/integration/Router/RouterTest.php
@@ -56,7 +56,7 @@ class RouterTest extends \MailPoetTest {
       [$this->accessControl, $this->container, $routerData]
     );
     $result = $router->init();
-    expect($result)->null();
+    verify($result)->null();
   }
 
   public function testItTerminatesRequestWhenEndpointNotFound() {
diff --git a/mailpoet/tests/integration/Segments/DynamicSegments/DynamicSegmentFilterRepositoryTest.php b/mailpoet/tests/integration/Segments/DynamicSegments/DynamicSegmentFilterRepositoryTest.php
index f2cc497a67..8b4d51a26d 100644
--- a/mailpoet/tests/integration/Segments/DynamicSegments/DynamicSegmentFilterRepositoryTest.php
+++ b/mailpoet/tests/integration/Segments/DynamicSegments/DynamicSegmentFilterRepositoryTest.php
@@ -38,7 +38,7 @@ class DynamicSegmentFilterRepositoryTest extends \MailPoetTest {
       DynamicSegmentFilterData::TYPE_USER_ROLE,
       UserRole::TYPE
     );
-    expect($dynamicFilter)->null();
+    verify($dynamicFilter)->null();
   }
 
   private function createSegment(string $name): SegmentEntity {
diff --git a/mailpoet/tests/integration/Segments/SegmentsRepositoryTest.php b/mailpoet/tests/integration/Segments/SegmentsRepositoryTest.php
index 44b6e641e2..05875463bc 100644
--- a/mailpoet/tests/integration/Segments/SegmentsRepositoryTest.php
+++ b/mailpoet/tests/integration/Segments/SegmentsRepositoryTest.php
@@ -58,7 +58,7 @@ class SegmentsRepositoryTest extends \MailPoetTest {
     $this->entityManager->refresh($segment1);
     $this->entityManager->refresh($segment2);
     verify($result)->equals(1);
-    expect($segment1->getDeletedAt())->null();
+    verify($segment1->getDeletedAt())->null();
     expect($segment2->getDeletedAt())->isInstanceOf(\DateTimeInterface::class);
   }
 
@@ -72,7 +72,7 @@ class SegmentsRepositoryTest extends \MailPoetTest {
     $this->entityManager->refresh($segment2);
     verify($result)->equals(1);
     expect($segment1->getDeletedAt())->isInstanceOf(\DateTimeInterface::class);
-    expect($segment2->getDeletedAt())->null();
+    verify($segment2->getDeletedAt())->null();
   }
 
   public function testItReturnsCountsOfSegmentsWithMultipleFilters(): void {
diff --git a/mailpoet/tests/integration/Segments/WPTest.php b/mailpoet/tests/integration/Segments/WPTest.php
index 5ed5aad363..63a7852473 100644
--- a/mailpoet/tests/integration/Segments/WPTest.php
+++ b/mailpoet/tests/integration/Segments/WPTest.php
@@ -544,7 +544,7 @@ class WPTest extends \MailPoetTest {
     $wpSegment->synchronizeUser($id);
     $subscriber1 = Subscriber::where("wp_user_id", $id)->findOne();
     verify($subscriber1->status)->equals(SubscriberEntity::STATUS_SUBSCRIBED);
-    expect($subscriber1->deletedAt)->null();
+    verify($subscriber1->deletedAt)->null();
   }
 
   public function testItDoesNotTrashNewUsersWhoIsWooCustomerToDisabledWPSegment(): void {
@@ -577,7 +577,7 @@ class WPTest extends \MailPoetTest {
     $wpSegment->synchronizeUser($id);
     $subscriber1 = Subscriber::where("wp_user_id", $id)->findOne();
     verify($subscriber1->status)->equals(SubscriberEntity::STATUS_UNCONFIRMED);
-    expect($subscriber1->deletedAt)->null();
+    verify($subscriber1->deletedAt)->null();
     remove_role('customer');
   }
 
diff --git a/mailpoet/tests/integration/Services/AuthorizedEmailsControllerTest.php b/mailpoet/tests/integration/Services/AuthorizedEmailsControllerTest.php
index 15566fff31..885e56e1cc 100644
--- a/mailpoet/tests/integration/Services/AuthorizedEmailsControllerTest.php
+++ b/mailpoet/tests/integration/Services/AuthorizedEmailsControllerTest.php
@@ -35,7 +35,7 @@ class AuthorizedEmailsControllerTest extends \MailPoetTest {
     $this->settings->set(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING, 'Error');
     $controller = $this->getController($authorizedEmailsFromApi = null);
     $controller->checkAuthorizedEmailAddresses();
-    expect($this->settings->get(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING))->null();
+    verify($this->settings->get(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING))->null();
   }
 
   public function testItSetsProperErrorForOldUsers() {
@@ -62,7 +62,7 @@ class AuthorizedEmailsControllerTest extends \MailPoetTest {
     $this->setMailPoetSendingMethod();
     $controller = $this->getController($authorizedEmailsFromApi = ['auth@email.com']);
     $controller->checkAuthorizedEmailAddresses();
-    expect($this->settings->get(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING))->null();
+    verify($this->settings->get(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING))->null();
   }
 
   public function testItSetEmptyErrorWhenDomainIsVerifiedButSenderAddressIsNotAuthorized() {
@@ -86,7 +86,7 @@ class AuthorizedEmailsControllerTest extends \MailPoetTest {
     ];
     $controller = $this->getControllerWithCustomMocks($mocks);
     $controller->checkAuthorizedEmailAddresses();
-    expect($this->settings->get(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING))->null();
+    verify($this->settings->get(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING))->null();
   }
 
   public function testItSetErrorForScheduledNewsletterWithUnauthorizedSender() {
@@ -120,7 +120,7 @@ class AuthorizedEmailsControllerTest extends \MailPoetTest {
     $controller = $this->getController($authorizedEmailsFromApi = ['auth@email.com']);
     $controller->checkAuthorizedEmailAddresses();
     $error = $this->settings->get(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING);
-    expect($error)->null();
+    verify($error)->null();
   }
 
   public function testItResetsUnauthorizedErrorInMailerLog() {
@@ -132,7 +132,7 @@ class AuthorizedEmailsControllerTest extends \MailPoetTest {
     $controller = $this->getController($authorizedEmailsFromApi = ['auth@email.com']);
     $controller->checkAuthorizedEmailAddresses();
     $error = MailerLog::getError();
-    expect($error)->null();
+    verify($error)->null();
   }
 
   public function testItResetsUnauthorizedErrorInMailerLogWhenDomainIsVerified() {
@@ -161,7 +161,7 @@ class AuthorizedEmailsControllerTest extends \MailPoetTest {
     $controller->checkAuthorizedEmailAddresses();
 
     $error = MailerLog::getError();
-    expect($error)->null();
+    verify($error)->null();
   }
 
   public function testItDoesNotResetOtherErrorInMailerLog() {
diff --git a/mailpoet/tests/integration/Services/BridgeApiTest.php b/mailpoet/tests/integration/Services/BridgeApiTest.php
index 20f7be1764..329f3f59cb 100644
--- a/mailpoet/tests/integration/Services/BridgeApiTest.php
+++ b/mailpoet/tests/integration/Services/BridgeApiTest.php
@@ -117,7 +117,7 @@ class BridgeApiTest extends \MailPoetTest {
       ->method('wpRemoteRetrieveResponseCode')
       ->willReturn(400);
     $result = $this->api->getAuthorizedSenderDomains();
-    expect($result)->null();
+    verify($result)->null();
   }
 
   public function testGetDomainsLogsErrorWhenResponseHasUnexpectedFormat() {
diff --git a/mailpoet/tests/integration/Services/BridgeTest.php b/mailpoet/tests/integration/Services/BridgeTest.php
index 0e08ee8025..73403a85a5 100644
--- a/mailpoet/tests/integration/Services/BridgeTest.php
+++ b/mailpoet/tests/integration/Services/BridgeTest.php
@@ -468,7 +468,7 @@ class BridgeTest extends \MailPoetTest {
     $this->bridge->storeMSSKeyAndState('cba', $result);
     $state = $this->getMssKeyState() ?? [];
     verify($state['state'])->equals(Bridge::KEY_VALID_UNDERPRIVILEGED);
-    expect($state['data'])->null();
+    verify($state['data'])->null();
   }
 
   public function testItPreservesPremiumKeyStateDataIfSubsequentCheckFails() {
@@ -534,7 +534,7 @@ class BridgeTest extends \MailPoetTest {
     $this->bridge->storePremiumKeyAndState('cba', $result);
     $state = $this->getPremiumKeyState() ?? [];
     verify($state['state'])->equals(Bridge::KEY_VALID_UNDERPRIVILEGED);
-    expect($state['data'])->null();
+    verify($state['data'])->null();
   }
 
   public function testItSavesAccessRestrictionForUnderprivilegePremiumKeys() {
@@ -608,7 +608,7 @@ class BridgeTest extends \MailPoetTest {
     $this->bridge->api = $api;
     $result = $this->bridge->$method('abc');
     expect($result)->notEmpty();
-    expect($result['data'])->null();
+    verify($result['data'])->null();
     verify($result['access_restriction'])->equals($expectedAccessRestriction);
   }
 
diff --git a/mailpoet/tests/integration/Settings/SettingsChangeHandlerTest.php b/mailpoet/tests/integration/Settings/SettingsChangeHandlerTest.php
index b13b591428..6016893005 100644
--- a/mailpoet/tests/integration/Settings/SettingsChangeHandlerTest.php
+++ b/mailpoet/tests/integration/Settings/SettingsChangeHandlerTest.php
@@ -44,7 +44,7 @@ class SettingsChangeHandlerTest extends \MailPoetTest {
 
   public function testItCreatesScheduledTaskForWoocommerceSync(): void {
     $task = $this->getScheduledTaskByType(WooCommerceSync::TASK_TYPE);
-    expect($task)->null();
+    verify($task)->null();
     $this->settingsChangeHandler->onSubscribeOldWoocommerceCustomersChange();
     $task = $this->getScheduledTaskByType(WooCommerceSync::TASK_TYPE);
     expect($task)->isInstanceOf(ScheduledTaskEntity::class);
@@ -67,7 +67,7 @@ class SettingsChangeHandlerTest extends \MailPoetTest {
 
   public function testItCreatesScheduledTaskForInactiveSubscribers(): void {
     $task = $this->getScheduledTaskByType(InactiveSubscribers::TASK_TYPE);
-    expect($task)->null();
+    verify($task)->null();
     $this->settingsChangeHandler->onInactiveSubscribersIntervalChange();
     $task = $this->getScheduledTaskByType(InactiveSubscribers::TASK_TYPE);
     expect($task)->isInstanceOf(ScheduledTaskEntity::class);
diff --git a/mailpoet/tests/integration/Settings/UserFlagsControllerTest.php b/mailpoet/tests/integration/Settings/UserFlagsControllerTest.php
index fd021b32ec..9986e025ea 100644
--- a/mailpoet/tests/integration/Settings/UserFlagsControllerTest.php
+++ b/mailpoet/tests/integration/Settings/UserFlagsControllerTest.php
@@ -82,7 +82,7 @@ class UserFlagsControllerTest extends \MailPoetTest {
       'userId' => $this->currentUserId,
       'name' => 'flag_1',
     ]);
-    expect($flag)->null();
+    verify($flag)->null();
   }
 
   private function createUserFlag($userId, $name, $value) {
diff --git a/mailpoet/tests/integration/Statistics/StatisticsOpensRepositoryTest.php b/mailpoet/tests/integration/Statistics/StatisticsOpensRepositoryTest.php
index 12cd21eed1..b355b0683f 100644
--- a/mailpoet/tests/integration/Statistics/StatisticsOpensRepositoryTest.php
+++ b/mailpoet/tests/integration/Statistics/StatisticsOpensRepositoryTest.php
@@ -43,11 +43,11 @@ class StatisticsOpensRepositoryTest extends \MailPoetTest {
     $this->repository->recalculateSegmentScore($segment);
     $newSubscriber = $this->subscribersRepository->findOneById($subscriber->getId());
     $this->assertInstanceOf(SubscriberEntity::class, $newSubscriber);
-    expect($newSubscriber->getEngagementScore())->null();
+    verify($newSubscriber->getEngagementScore())->null();
     expect($newSubscriber->getEngagementScoreUpdatedAt())->notNull();
     $newSegment = $this->segmentsRepository->findOneById($segment->getId());
     $this->assertInstanceOf(SegmentEntity::class, $newSegment);
-    expect($newSegment->getAverageEngagementScore())->null();
+    verify($newSegment->getAverageEngagementScore())->null();
     expect($newSegment->getAverageEngagementScoreUpdatedAt())->notNull();
   }
 
@@ -62,7 +62,7 @@ class StatisticsOpensRepositoryTest extends \MailPoetTest {
     $this->repository->recalculateSegmentScore($segment);
     $newSubscriber = $this->subscribersRepository->findOneById($subscriber->getId());
     $this->assertInstanceOf(SubscriberEntity::class, $newSubscriber);
-    expect($newSubscriber->getEngagementScore())->null();
+    verify($newSubscriber->getEngagementScore())->null();
     expect($newSubscriber->getEngagementScoreUpdatedAt())->notNull();
     $updated = $newSubscriber->getEngagementScoreUpdatedAt();
     $this->assertInstanceOf(\DateTimeInterface::class, $updated);
@@ -70,7 +70,7 @@ class StatisticsOpensRepositoryTest extends \MailPoetTest {
     verify($scoreUpdatedAt->isAfter((new CarbonImmutable())->subMinutes(5)))->true();
     $newSegment = $this->segmentsRepository->findOneById($segment->getId());
     $this->assertInstanceOf(SegmentEntity::class, $newSegment);
-    expect($newSegment->getAverageEngagementScore())->null();
+    verify($newSegment->getAverageEngagementScore())->null();
     expect($newSegment->getAverageEngagementScoreUpdatedAt())->notNull();
     $updated = $newSegment->getAverageEngagementScoreUpdatedAt();
     $this->assertInstanceOf(\DateTimeInterface::class, $updated);
@@ -88,7 +88,7 @@ class StatisticsOpensRepositoryTest extends \MailPoetTest {
     verify($subscriber->getEngagementScore())->equals(5);
     $this->repository->recalculateSubscriberScore($subscriber);
     $this->entityManager->refresh($subscriber);
-    expect($subscriber->getEngagementScore())->null();
+    verify($subscriber->getEngagementScore())->null();
   }
 
   public function testItUpdatesScore() {
diff --git a/mailpoet/tests/integration/Statistics/Track/ClicksTest.php b/mailpoet/tests/integration/Statistics/Track/ClicksTest.php
index a2beff5fed..63b5e80bbe 100644
--- a/mailpoet/tests/integration/Statistics/Track/ClicksTest.php
+++ b/mailpoet/tests/integration/Statistics/Track/ClicksTest.php
@@ -342,7 +342,7 @@ class ClicksTest extends \MailPoetTest {
     $trackedClicks = $clicksRepository->findAll();
     expect($trackedClicks)->count(1);
     $click = $trackedClicks[0];
-    expect($click->getUserAgent())->null();
+    verify($click->getUserAgent())->null();
     verify($click->getUserAgentType())->equals(UserAgentEntity::USER_AGENT_TYPE_HUMAN);
     // Track Machine User Agent
     $machineUserAgentName = UserAgentEntity::MACHINE_USER_AGENTS[0];
@@ -351,7 +351,7 @@ class ClicksTest extends \MailPoetTest {
     $trackedClicks = $clicksRepository->findAll();
     expect($trackedClicks)->count(1);
     $click = $trackedClicks[0];
-    expect($click->getUserAgent())->null();
+    verify($click->getUserAgent())->null();
     verify($click->getUserAgentType())->equals(UserAgentEntity::USER_AGENT_TYPE_HUMAN);
   }
 
@@ -377,7 +377,7 @@ class ClicksTest extends \MailPoetTest {
     $trackedClicks = $clicksRepository->findAll();
     expect($trackedClicks)->count(1);
     $click = $trackedClicks[0];
-    expect($click->getUserAgent())->null();
+    verify($click->getUserAgent())->null();
     verify($click->getUserAgentType())->equals(UserAgentEntity::USER_AGENT_TYPE_HUMAN);
     // Track Machine User Agent
     $humanUserAgentName = 'User Agent';
diff --git a/mailpoet/tests/integration/Statistics/Track/OpensTest.php b/mailpoet/tests/integration/Statistics/Track/OpensTest.php
index b96c0236b4..8c93caacc9 100644
--- a/mailpoet/tests/integration/Statistics/Track/OpensTest.php
+++ b/mailpoet/tests/integration/Statistics/Track/OpensTest.php
@@ -308,7 +308,7 @@ class OpensTest extends \MailPoetTest {
     expect($openEntities)->count(1);
     $openEntity = reset($openEntities);
     $this->assertInstanceOf(StatisticsOpenEntity::class, $openEntity);
-    expect($openEntity->getUserAgent())->null();
+    verify($openEntity->getUserAgent())->null();
     verify($openEntity->getUserAgentType())->equals(UserAgentEntity::USER_AGENT_TYPE_HUMAN);
     // Track Machine User Agent
     $machineUserAgentName = UserAgentEntity::MACHINE_USER_AGENTS[0];
@@ -319,7 +319,7 @@ class OpensTest extends \MailPoetTest {
     expect($openEntities)->count(1);
     $openEntity = reset($openEntities);
     $this->assertInstanceOf(StatisticsOpenEntity::class, $openEntity);
-    expect($openEntity->getUserAgent())->null();
+    verify($openEntity->getUserAgent())->null();
     verify($openEntity->getUserAgentType())->equals(UserAgentEntity::USER_AGENT_TYPE_HUMAN);
   }
 
@@ -339,7 +339,7 @@ class OpensTest extends \MailPoetTest {
     expect($openEntities)->count(1);
     $openEntity = reset($openEntities);
     $this->assertInstanceOf(StatisticsOpenEntity::class, $openEntity);
-    expect($openEntity->getUserAgent())->null();
+    verify($openEntity->getUserAgent())->null();
     verify($openEntity->getUserAgentType())->equals(UserAgentEntity::USER_AGENT_TYPE_HUMAN);
     // Track Human User Agent
     $humanUserAgentName = 'User Agent';
diff --git a/mailpoet/tests/integration/Subscribers/ConfirmationEmailMailerTest.php b/mailpoet/tests/integration/Subscribers/ConfirmationEmailMailerTest.php
index d462c763ac..7049847944 100644
--- a/mailpoet/tests/integration/Subscribers/ConfirmationEmailMailerTest.php
+++ b/mailpoet/tests/integration/Subscribers/ConfirmationEmailMailerTest.php
@@ -178,7 +178,7 @@ class ConfirmationEmailMailerTest extends \MailPoetTest {
       $exceptionMessage = $e->getMessage();
     }
     verify($exceptionMessage)->equals(__('There was an error when sending a confirmation email for your subscription. Please contact the website owner.', 'mailpoet'));
-    expect(MailerLog::getError())->null();
+    verify(MailerLog::getError())->null();
   }
 
   public function testItDoesntSendWhenMSSIsActiveAndConfirmationEmailIsNotAuthorized() {
diff --git a/mailpoet/tests/integration/Subscribers/EngagementDataBackfillerTest.php b/mailpoet/tests/integration/Subscribers/EngagementDataBackfillerTest.php
index b7c094056b..482595c820 100644
--- a/mailpoet/tests/integration/Subscribers/EngagementDataBackfillerTest.php
+++ b/mailpoet/tests/integration/Subscribers/EngagementDataBackfillerTest.php
@@ -81,8 +81,8 @@ class EngagementDataBackfillerTest extends \MailPoetTest {
     $sub1->setLastPurchaseAt(null);
     $sub2->setLastPurchaseAt(null);
     $this->entityManager->flush();
-    expect($sub2->getLastPurchaseAt())->null();
-    expect($sub1->getLastPurchaseAt())->null();
+    verify($sub2->getLastPurchaseAt())->null();
+    verify($sub1->getLastPurchaseAt())->null();
 
     $this->backfiller->updateBatch([$sub1, $sub2]);
 
@@ -160,10 +160,10 @@ class EngagementDataBackfillerTest extends \MailPoetTest {
 
     $this->entityManager->flush();
 
-    expect($sub1->getLastOpenAt())->null();
-    expect($sub2->getLastOpenAt())->null();
-    expect($sub3->getLastOpenAt())->null();
-    expect($sub4->getLastOpenAt())->null();
+    verify($sub1->getLastOpenAt())->null();
+    verify($sub2->getLastOpenAt())->null();
+    verify($sub3->getLastOpenAt())->null();
+    verify($sub4->getLastOpenAt())->null();
 
     $this->backfiller->updateBatch([$sub1, $sub2, $sub3, $sub4]);
 
@@ -179,7 +179,7 @@ class EngagementDataBackfillerTest extends \MailPoetTest {
     verify($sub1->getLastOpenAt()->getTimestamp())->equals($newer->getTimestamp());
     verify($sub2->getLastOpenAt()->getTimestamp())->equals($sub2date->getTimestamp());
     verify($sub3->getLastOpenAt()->getTimestamp())->equals($sub3date->getTimestamp());
-    expect($sub4->getLastOpenAt())->null();
+    verify($sub4->getLastOpenAt())->null();
   }
 
   public function testItRetrievesClicksData(): void {
@@ -249,10 +249,10 @@ class EngagementDataBackfillerTest extends \MailPoetTest {
 
     $this->entityManager->flush();
 
-    expect($sub1->getLastClickAt())->null();
-    expect($sub2->getLastClickAt())->null();
-    expect($sub3->getLastClickAt())->null();
-    expect($sub4->getLastClickAt())->null();
+    verify($sub1->getLastClickAt())->null();
+    verify($sub2->getLastClickAt())->null();
+    verify($sub3->getLastClickAt())->null();
+    verify($sub4->getLastClickAt())->null();
 
     $this->backfiller->updateBatch([$sub1, $sub2, $sub3, $sub4]);
 
@@ -269,7 +269,7 @@ class EngagementDataBackfillerTest extends \MailPoetTest {
     verify($sub1->getLastClickAt()->getTimestamp())->equals($newer->getTimestamp());
     verify($sub2->getLastClickAt()->getTimestamp())->equals($sub2date->getTimestamp());
     verify($sub3->getLastClickAt()->getTimestamp())->equals($sub3date->getTimestamp());
-    expect($sub4->getLastOpenAt())->null();
+    verify($sub4->getLastOpenAt())->null();
   }
 
   public function testItRetrievesSendingData(): void {
@@ -339,10 +339,10 @@ class EngagementDataBackfillerTest extends \MailPoetTest {
 
     $this->entityManager->flush();
 
-    expect($sub1->getLastSendingAt())->null();
-    expect($sub2->getLastSendingAt())->null();
-    expect($sub3->getLastSendingAt())->null();
-    expect($sub4->getLastSendingAt())->null();
+    verify($sub1->getLastSendingAt())->null();
+    verify($sub2->getLastSendingAt())->null();
+    verify($sub3->getLastSendingAt())->null();
+    verify($sub4->getLastSendingAt())->null();
 
     $this->backfiller->updateBatch([$sub1, $sub2, $sub3, $sub4]);
 
@@ -358,7 +358,7 @@ class EngagementDataBackfillerTest extends \MailPoetTest {
     verify($sub1->getLastSendingAt()->getTimestamp())->equals($newer->getTimestamp());
     verify($sub2->getLastSendingAt()->getTimestamp())->equals($sub2date->getTimestamp());
     verify($sub3->getLastSendingAt()->getTimestamp())->equals($sub3date->getTimestamp());
-    expect($sub4->getLastSendingAt())->null();
+    verify($sub4->getLastSendingAt())->null();
   }
 
   public function testItRetrievesSubscribersInBatches(): void {
diff --git a/mailpoet/tests/integration/Subscribers/ImportExport/ImportExportFactoryTest.php b/mailpoet/tests/integration/Subscribers/ImportExport/ImportExportFactoryTest.php
index 880e125867..b779661311 100644
--- a/mailpoet/tests/integration/Subscribers/ImportExport/ImportExportFactoryTest.php
+++ b/mailpoet/tests/integration/Subscribers/ImportExport/ImportExportFactoryTest.php
@@ -74,12 +74,12 @@ class ImportExportFactoryTest extends \MailPoetTest {
 
     $subscriber = $this->subscribersRepository->findOneBy(['email' => 'mike@mailpoet.com']);
     $this->assertInstanceOf(SubscriberEntity::class, $subscriber);
-    expect($subscriber->getDeletedAt())->null();
+    verify($subscriber->getDeletedAt())->null();
 
     $this->subscribersRepository->bulkTrash([$subscriber->getId()]);
 
     $subscriber = $this->subscribersRepository->findOneBy(['email' => 'mike@mailpoet.com', 'deletedAt' => null]);
-    expect($subscriber)->null();
+    verify($subscriber)->null();
 
     $this->clearSubscribersCountCache();
     $segments = $this->importFactory->getSegments();
diff --git a/mailpoet/tests/integration/Subscribers/SubscriberActionsTest.php b/mailpoet/tests/integration/Subscribers/SubscriberActionsTest.php
index 4e304cb7d2..db5e209619 100644
--- a/mailpoet/tests/integration/Subscribers/SubscriberActionsTest.php
+++ b/mailpoet/tests/integration/Subscribers/SubscriberActionsTest.php
@@ -118,7 +118,7 @@ class SubscriberActionsTest extends \MailPoetTest {
       $newsletter,
       ScheduledTaskEntity::STATUS_SCHEDULED
     );
-    expect($scheduledNotification)->null();
+    verify($scheduledNotification)->null();
   }
 
   public function testItCannotSubscribeWithReservedColumns() {
@@ -150,13 +150,13 @@ class SubscriberActionsTest extends \MailPoetTest {
 
     $createdAt = $subscriber->getCreatedAt();
     $this->assertInstanceOf(\DateTimeInterface::class, $createdAt);
-    expect($subscriber->getWpUserId())->null();
+    verify($subscriber->getWpUserId())->null();
     verify($subscriber->getIsWoocommerceUser())->equals(0);
     verify($subscriber->getStatus())->equals(SubscriberEntity::STATUS_UNCONFIRMED);
     expect($createdAt->format('Y-m-d H:i:s'))->notEquals('1984-03-09 00:00:01');
     expect($subscriber->getUpdatedAt()->format('Y-m-d H:i:s'))->notEquals('1984-03-09 00:00:02');
     verify($createdAt->getTimestamp())->equals($subscriber->getUpdatedAt()->getTimestamp(), 2);
-    expect($subscriber->getDeletedAt())->null();
+    verify($subscriber->getDeletedAt())->null();
   }
 
   public function testItOverwritesSubscriberDataWhenConfirmationIsDisabled() {
diff --git a/mailpoet/tests/integration/Subscribers/SubscribersRepositoryTest.php b/mailpoet/tests/integration/Subscribers/SubscribersRepositoryTest.php
index 459bb42a89..f71e78d2fb 100644
--- a/mailpoet/tests/integration/Subscribers/SubscribersRepositoryTest.php
+++ b/mailpoet/tests/integration/Subscribers/SubscribersRepositoryTest.php
@@ -55,7 +55,7 @@ class SubscribersRepositoryTest extends \MailPoetTest {
     // don't trashed subscriber
     $subscriberThree = $this->repository->findOneById($subscriberThreeId);
     $this->assertInstanceOf(SubscriberEntity::class, $subscriberThree);
-    expect($subscriberThree->getDeletedAt())->null();
+    verify($subscriberThree->getDeletedAt())->null();
   }
 
   public function testItBulkRestoreTrashedSubscribers(): void {
@@ -74,7 +74,7 @@ class SubscribersRepositoryTest extends \MailPoetTest {
     // restored subscriber
     $subscriberOne = $this->repository->findOneById($subscriberOneId);
     $this->assertInstanceOf(SubscriberEntity::class, $subscriberOne);
-    expect($subscriberOne->getDeletedAt())->null();
+    verify($subscriberOne->getDeletedAt())->null();
     // don't restored subscriber
     $subscriberTwo = $this->repository->findOneById($subscriberTwoId);
     $this->assertInstanceOf(SubscriberEntity::class, $subscriberTwo);
@@ -86,9 +86,9 @@ class SubscribersRepositoryTest extends \MailPoetTest {
     $subscriberTwo = $this->createSubscriber('two@e.com');
     $subscriberThree = $this->createSubscriber('three@e.com');
 
-    expect($subscriberOne->getLastSendingAt())->null();
-    expect($subscriberTwo->getLastSendingAt())->null();
-    expect($subscriberThree->getLastSendingAt())->null();
+    verify($subscriberOne->getLastSendingAt())->null();
+    verify($subscriberTwo->getLastSendingAt())->null();
+    verify($subscriberThree->getLastSendingAt())->null();
     $idsToUpdate = [
       $subscriberOne->getId(),
       $subscriberThree->getId(),
@@ -100,7 +100,7 @@ class SubscribersRepositoryTest extends \MailPoetTest {
     $this->repository->refresh($subscriberThree);
     $this->assertInstanceOf(DateTimeInterface::class, $subscriberOne->getLastSendingAt());
     verify($subscriberOne->getLastSendingAt()->getTimestamp())->equals($now->getTimestamp());
-    expect($subscriberTwo->getLastSendingAt())->null();
+    verify($subscriberTwo->getLastSendingAt())->null();
     $this->assertInstanceOf(DateTimeInterface::class, $subscriberThree->getLastSendingAt());
     verify($subscriberThree->getLastSendingAt()->getTimestamp())->equals($now->getTimestamp());
   }
@@ -110,9 +110,9 @@ class SubscribersRepositoryTest extends \MailPoetTest {
     $subscriberTwo = $this->createSubscriber('two@e.com');
     $subscriberThree = $this->createSubscriber('three@e.com');
 
-    expect($subscriberOne->getEngagementScoreUpdatedAt())->null();
-    expect($subscriberTwo->getEngagementScoreUpdatedAt())->null();
-    expect($subscriberThree->getEngagementScoreUpdatedAt())->null();
+    verify($subscriberOne->getEngagementScoreUpdatedAt())->null();
+    verify($subscriberTwo->getEngagementScoreUpdatedAt())->null();
+    verify($subscriberThree->getEngagementScoreUpdatedAt())->null();
     $idsToUpdate = [
       $subscriberOne->getId(),
       $subscriberThree->getId(),
@@ -124,7 +124,7 @@ class SubscribersRepositoryTest extends \MailPoetTest {
     $this->repository->refresh($subscriberThree);
     $this->assertInstanceOf(DateTimeInterface::class, $subscriberOne->getEngagementScoreUpdatedAt());
     verify($subscriberOne->getEngagementScoreUpdatedAt()->getTimestamp())->equals($now->getTimestamp());
-    expect($subscriberTwo->getEngagementScoreUpdatedAt())->null();
+    verify($subscriberTwo->getEngagementScoreUpdatedAt())->null();
     $this->assertInstanceOf(DateTimeInterface::class, $subscriberThree->getEngagementScoreUpdatedAt());
     verify($subscriberThree->getEngagementScoreUpdatedAt()->getTimestamp())->equals($now->getTimestamp());
   }
@@ -160,9 +160,9 @@ class SubscribersRepositoryTest extends \MailPoetTest {
     $this->repository->refresh($subscriberTwo);
     $this->repository->refresh($subscriberThree);
 
-    expect($subscriberOne->getEngagementScoreUpdatedAt())->null();
+    verify($subscriberOne->getEngagementScoreUpdatedAt())->null();
     $this->assertInstanceOf(DateTimeInterface::class, $subscriberTwo->getEngagementScoreUpdatedAt());
-    expect($subscriberOne->getEngagementScoreUpdatedAt())->null();
+    verify($subscriberOne->getEngagementScoreUpdatedAt())->null();
   }
 
   public function testItBulkDeleteSubscribers(): void {
@@ -185,9 +185,9 @@ class SubscribersRepositoryTest extends \MailPoetTest {
     $this->entityManager->clear();
 
     // deleted subscriber
-    expect($this->repository->findOneById($subscriberOneId))->null();
-    expect($this->subscriberSegmentRepository->findOneBy(['subscriber' => $subscriberOneId]))->null();
-    expect($this->subscriberCustomFieldRepository->findOneBy(['subscriber' => $subscriberOneId]))->null();
+    verify($this->repository->findOneById($subscriberOneId))->null();
+    verify($this->subscriberSegmentRepository->findOneBy(['subscriber' => $subscriberOneId]))->null();
+    verify($this->subscriberCustomFieldRepository->findOneBy(['subscriber' => $subscriberOneId]))->null();
     // don't restored subscriber
     $subscriberTwo = $this->repository->findOneById($subscriberTwoId);
     $this->assertInstanceOf(SubscriberEntity::class, $subscriberTwo);
@@ -218,7 +218,7 @@ class SubscribersRepositoryTest extends \MailPoetTest {
 
     // subscriber with removed segment one
     expect($this->repository->findOneById($subscriberOneId))->notNull();
-    expect($this->subscriberSegmentRepository->findOneBy([
+    verify($this->subscriberSegmentRepository->findOneBy([
       'subscriber' => $subscriberOneId,
       'segment' => $segmentOneId,
     ]))->null();
@@ -229,7 +229,7 @@ class SubscribersRepositoryTest extends \MailPoetTest {
 
     // subscriber with removed segment two
     expect($this->repository->findOneById($subscriberTwoId))->notNull();
-    expect($this->subscriberSegmentRepository->findOneBy([
+    verify($this->subscriberSegmentRepository->findOneBy([
       'subscriber' => $subscriberTwoId,
       'segment' => $segmentTwoId,
     ]))->null();
@@ -342,7 +342,7 @@ class SubscribersRepositoryTest extends \MailPoetTest {
 
     // subscriber moved to segment two
     expect($this->repository->findOneById($subscriberOneId))->notNull();
-    expect($this->subscriberSegmentRepository->findOneBy([
+    verify($this->subscriberSegmentRepository->findOneBy([
       'subscriber' => $subscriberOneId,
       'segment' => $segmentOneId,
     ]))->null();
@@ -353,7 +353,7 @@ class SubscribersRepositoryTest extends \MailPoetTest {
 
     // subscriber which stay in segment two
     expect($this->repository->findOneById($subscriberTwoId))->notNull();
-    expect($this->subscriberSegmentRepository->findOneBy([
+    verify($this->subscriberSegmentRepository->findOneBy([
       'subscriber' => $subscriberTwoId,
       'segment' => $segmentOneId,
     ]))->null();
diff --git a/mailpoet/tests/integration/Subscription/FormTest.php b/mailpoet/tests/integration/Subscription/FormTest.php
index 4babc80d0c..cc5da68c3a 100644
--- a/mailpoet/tests/integration/Subscription/FormTest.php
+++ b/mailpoet/tests/integration/Subscription/FormTest.php
@@ -84,7 +84,7 @@ class FormTest extends \MailPoetTest {
     $result = $formController->onSubmit($this->requestData);
     expect($this->subscribersRepository->findOneBy(['email' => $this->testEmail]))->notEmpty();
     verify($result['mailpoet_success'])->equals($this->form->getId());
-    expect($result['mailpoet_error'])->null();
+    verify($result['mailpoet_error'])->null();
   }
 
   public function testItSubscribesAndRedirectsToCustomUrlWithSuccessResponse() {
@@ -122,7 +122,7 @@ class FormTest extends \MailPoetTest {
     $result = $formController->onSubmit($requestData);
     expect($this->subscribersRepository->findAll())->isEmpty();
     verify($result['mailpoet_error'])->equals($this->form->getId());
-    expect($result['mailpoet_success'])->null();
+    verify($result['mailpoet_success'])->null();
   }
 
   public function testItDoesNotSubscribeAndRedirectsToRedirectUrlIfPresent() {
diff --git a/mailpoet/tests/integration/Util/Notices/HeadersAlreadySentNoticeTest.php b/mailpoet/tests/integration/Util/Notices/HeadersAlreadySentNoticeTest.php
index 98d6df9f9f..aed88ebf7c 100644
--- a/mailpoet/tests/integration/Util/Notices/HeadersAlreadySentNoticeTest.php
+++ b/mailpoet/tests/integration/Util/Notices/HeadersAlreadySentNoticeTest.php
@@ -44,7 +44,7 @@ class HeadersAlreadySentNoticeTest extends \MailPoetTest {
       ['headersSent' => false]
     );
     $notice = $headersAlreadySentNotice->init(true);
-    expect($notice)->null();
+    verify($notice)->null();
   }
 
   public function testItPrintsWarningWhenWhitespaceIsInBuffer() {
@@ -67,7 +67,7 @@ class HeadersAlreadySentNoticeTest extends \MailPoetTest {
       ['headersSent' => true]
     );
     $warning = $headersAlreadySentNotice->init(false);
-    expect($warning)->null();
+    verify($warning)->null();
   }
 
   public function testItPrintsNoWarningWhenDismissed() {
@@ -78,7 +78,7 @@ class HeadersAlreadySentNoticeTest extends \MailPoetTest {
     );
     $headersAlreadySentNotice->disable();
     $warning = $headersAlreadySentNotice->init(true);
-    expect($warning)->null();
+    verify($warning)->null();
   }
 
   public function testItPrintsCaptchaAndTrackingMessagesIfEnabled() {
@@ -105,6 +105,6 @@ class HeadersAlreadySentNoticeTest extends \MailPoetTest {
   public function testItPrintsNoMessagesWhenCaptchaAndTrackingDisabled() {
     $headersAlreadySentNotice = Stub::make(HeadersAlreadySentNotice::class);
     $notice = $headersAlreadySentNotice->display(false, false);
-    expect($notice)->null();
+    verify($notice)->null();
   }
 }
diff --git a/mailpoet/tests/integration/Util/Notices/InactiveSubscribersNoticeTest.php b/mailpoet/tests/integration/Util/Notices/InactiveSubscribersNoticeTest.php
index 6bd17cfedc..bbeed8eaa9 100644
--- a/mailpoet/tests/integration/Util/Notices/InactiveSubscribersNoticeTest.php
+++ b/mailpoet/tests/integration/Util/Notices/InactiveSubscribersNoticeTest.php
@@ -27,7 +27,7 @@ class InactiveSubscribersNoticeTest extends \MailPoetTest {
 
     $this->notice->disable();
     $result = $this->notice->init(true);
-    expect($result)->null();
+    verify($result)->null();
   }
 
   public function testItDisplaysWhenInactiveTimeRangeIsTheDefaultValue() {
@@ -49,14 +49,14 @@ class InactiveSubscribersNoticeTest extends \MailPoetTest {
     $settingsFactory->withDeactivateSubscriberAfter3Months();
 
     $result = $this->notice->init(true);
-    expect($result)->null();
+    verify($result)->null();
   }
 
   public function testItDoesntDisplayWhenNotEnoughInactiveSubscribers() {
     $this->createSubscribers(49);
 
     $result = $this->notice->init(true);
-    expect($result)->null();
+    verify($result)->null();
   }
 
   public function _before() {
diff --git a/mailpoet/tests/integration/Util/Notices/PHPVersionWarningsTest.php b/mailpoet/tests/integration/Util/Notices/PHPVersionWarningsTest.php
index 28032ad3d7..b84495a301 100644
--- a/mailpoet/tests/integration/Util/Notices/PHPVersionWarningsTest.php
+++ b/mailpoet/tests/integration/Util/Notices/PHPVersionWarningsTest.php
@@ -58,13 +58,13 @@ class PHPVersionWarningsTest extends \MailPoetTest {
 
   public function testItPrintsNoWarningWhenDisabled() {
     $warning = $this->phpVersionWarning->init('5.5.3', false);
-    expect($warning)->null();
+    verify($warning)->null();
   }
 
   public function testItPrintsNoWarningWhenDismised() {
     $this->phpVersionWarning->init('5.5.3', true);
     $this->phpVersionWarning->disable();
     $warning = $this->phpVersionWarning->init('5.5.3', true);
-    expect($warning)->null();
+    verify($warning)->null();
   }
 }
diff --git a/mailpoet/tests/integration/Util/Notices/PendingApprovalNoticeTest.php b/mailpoet/tests/integration/Util/Notices/PendingApprovalNoticeTest.php
index e2b5d3c044..cb4edf59f2 100644
--- a/mailpoet/tests/integration/Util/Notices/PendingApprovalNoticeTest.php
+++ b/mailpoet/tests/integration/Util/Notices/PendingApprovalNoticeTest.php
@@ -36,7 +36,7 @@ class PendingApprovalNoticeTest extends \MailPoetTest {
     $this->settings->set('mta.method', Mailer::METHOD_MAILPOET);
 
     $result = $this->notice->init(true);
-    expect($result)->null();
+    verify($result)->null();
   }
 
   public function testItDoesNotDisplayWhenDisabled(): void {
@@ -44,7 +44,7 @@ class PendingApprovalNoticeTest extends \MailPoetTest {
     $this->settings->set('mta.method', Mailer::METHOD_MAILPOET);
 
     $result = $this->notice->init(false);
-    expect($result)->null();
+    verify($result)->null();
   }
 
   public function testItDoesNotDisplayWhenNotUsingMailPoet(): void {
@@ -52,7 +52,7 @@ class PendingApprovalNoticeTest extends \MailPoetTest {
     $this->settings->set('mta.method', Mailer::METHOD_PHPMAIL);
 
     $result = $this->notice->init(true);
-    expect($result)->null();
+    verify($result)->null();
   }
 
   public function testItDoesNotDisplayWhenApproved(): void {
@@ -60,6 +60,6 @@ class PendingApprovalNoticeTest extends \MailPoetTest {
     $this->settings->set('mta.method', Mailer::METHOD_MAILPOET);
 
     $result = $this->notice->init(true);
-    expect($result)->null();
+    verify($result)->null();
   }
 }
diff --git a/mailpoet/tests/integration/WooCommerce/SubscriberEngagementTest.php b/mailpoet/tests/integration/WooCommerce/SubscriberEngagementTest.php
index 3c088e0ae6..0ad5d8ac4b 100644
--- a/mailpoet/tests/integration/WooCommerce/SubscriberEngagementTest.php
+++ b/mailpoet/tests/integration/WooCommerce/SubscriberEngagementTest.php
@@ -58,13 +58,13 @@ class SubscriberEngagementTest extends \MailPoetTest {
       ->willReturn(false);
     $this->subscriberEngagement->updateSubscriberEngagement(1);
     $this->entityManager->refresh($subscriber);
-    expect($subscriber->getLastEngagementAt())->null();
+    verify($subscriber->getLastEngagementAt())->null();
   }
 
   public function testItUpdatesTimestampsWhenOrderChangesToPaidStatus(): void {
     $subscriber = $this->createSubscriber();
-    expect($subscriber->getLastEngagementAt())->null();
-    expect($subscriber->getLastPurchaseAt())->null();
+    verify($subscriber->getLastEngagementAt())->null();
+    verify($subscriber->getLastPurchaseAt())->null();
     $order = $this->tester->createWooCommerceOrder(['status' => 'pending', 'billing_email' => $subscriber->getEmail()]);
     $order->set_status('processing');
     $order->save();
diff --git a/mailpoet/tests/unit/Cron/CronTriggerTest.php b/mailpoet/tests/unit/Cron/CronTriggerTest.php
index c8f8c817d7..3065cb1824 100644
--- a/mailpoet/tests/unit/Cron/CronTriggerTest.php
+++ b/mailpoet/tests/unit/Cron/CronTriggerTest.php
@@ -57,7 +57,7 @@ class CronTriggerTest extends \MailPoetUnitTest {
       },
     ]);
     $cronTrigger = $this->createCronTrigger($settingsMock, $wordPressTrigger);
-    expect($cronTrigger->init())->null();
+    verify($cronTrigger->init())->null();
   }
 
   private function createCronTrigger(
diff --git a/mailpoet/tests/unit/DI/ContainerWrapperTest.php b/mailpoet/tests/unit/DI/ContainerWrapperTest.php
index 0ff68a94ff..0e6e852488 100644
--- a/mailpoet/tests/unit/DI/ContainerWrapperTest.php
+++ b/mailpoet/tests/unit/DI/ContainerWrapperTest.php
@@ -24,7 +24,7 @@ class ContainerWrapperTest extends \MailPoetUnitTest {
 
   public function testItProvidesPremiumContainerIfAvailable() {
     $instance = new ContainerWrapper(new ContainerBuilder());
-    expect($instance->getPremiumContainer())->null();
+    verify($instance->getPremiumContainer())->null();
 
     $instance = new ContainerWrapper(new ContainerBuilder(), new ContainerBuilder());
     expect($instance->getPremiumContainer())->isInstanceOf(ContainerBuilder::class);
diff --git a/mailpoet/tests/unit/Entities/SubscriberEntityTest.php b/mailpoet/tests/unit/Entities/SubscriberEntityTest.php
index 8f0fdb79a1..b9e4d083b5 100644
--- a/mailpoet/tests/unit/Entities/SubscriberEntityTest.php
+++ b/mailpoet/tests/unit/Entities/SubscriberEntityTest.php
@@ -11,6 +11,6 @@ class SubscriberEntityTest extends \MailPoetUnitTest {
 
   public function testMagicGetterReturnsNullForUnknown() {
     $subscriber = new SubscriberEntity();
-    expect($subscriber->non_existing_property)->null();// phpcs:ignore Squiz.NamingConventions.ValidVariableName.MemberNotCamelCaps
+    verify($subscriber->non_existing_property)->null();// phpcs:ignore Squiz.NamingConventions.ValidVariableName.MemberNotCamelCaps
   }
 }
diff --git a/mailpoet/tests/unit/Form/Block/ColumnTest.php b/mailpoet/tests/unit/Form/Block/ColumnTest.php
index bd8ee168b9..c9ed8075a6 100644
--- a/mailpoet/tests/unit/Form/Block/ColumnTest.php
+++ b/mailpoet/tests/unit/Form/Block/ColumnTest.php
@@ -49,7 +49,7 @@ class ColumnTest extends \MailPoetUnitTest {
     $html = $this->columns->render($block, 'content');
     $column = $this->htmlParser->getElementByXpath($html, '//div[@class="mailpoet_form_column"]');
     $this->assertInstanceOf(\DOMNamedNodeMap::class, $column->attributes);
-    expect($column->attributes->getNamedItem('style'))->null();
+    verify($column->attributes->getNamedItem('style'))->null();
   }
 
   public function testItShouldRenderWidthBackwardCompatible() {
diff --git a/mailpoet/tests/unit/Form/DisplayFormInWPContentTest.php b/mailpoet/tests/unit/Form/DisplayFormInWPContentTest.php
index dd6fe9551f..68d1e7f9a9 100644
--- a/mailpoet/tests/unit/Form/DisplayFormInWPContentTest.php
+++ b/mailpoet/tests/unit/Form/DisplayFormInWPContentTest.php
@@ -276,7 +276,7 @@ class DisplayFormInWPContentTest extends \MailPoetUnitTest {
     $this->wp->expects($this->never())->method('isSingle');
     $this->wp->expects($this->never())->method('isSingular');
     $this->repository->expects($this->never())->method('findAll');
-    expect($this->hook->contentDisplay(null))->null();
+    verify($this->hook->contentDisplay(null))->null();
     verify($this->hook->contentDisplay([1,2,3]))->equals([1,2,3]);
     verify($this->hook->contentDisplay(1))->equals(1);
     verify($this->hook->contentDisplay(1.1))->equals(1.1);