diff --git a/mailpoet/tests/integration/Mailer/Methods/MailPoetAPITest.php b/mailpoet/tests/integration/Mailer/Methods/MailPoetAPITest.php
index ebd9a311a0..5d9d8fc7e7 100644
--- a/mailpoet/tests/integration/Mailer/Methods/MailPoetAPITest.php
+++ b/mailpoet/tests/integration/Mailer/Methods/MailPoetAPITest.php
@@ -44,7 +44,7 @@ class MailPoetAPITest extends \MailPoetTest {
       $this->settings['api_key'],
       $this->sender,
       $this->replyTo,
-      new MailPoetMapper(),
+      $this->diContainer->get(MailPoetMapper::class),
       $this->makeEmpty(AuthorizedEmailsController::class)
     );
     $this->subscriber = 'Recipient <blackhole@mailpoet.com>';
@@ -85,7 +85,7 @@ class MailPoetAPITest extends \MailPoetTest {
       $this->settings['api_key'],
       $this->sender,
       $replyTo,
-      new MailPoetMapper(),
+      $this->diContainer->get(MailPoetMapper::class),
       $this->makeEmpty(AuthorizedEmailsController::class)
     );
     $body = $mailer->getBody($this->newsletter, $this->subscriber);
@@ -274,7 +274,7 @@ class MailPoetAPITest extends \MailPoetTest {
       $this->settings['api_key'],
       $this->sender,
       $this->replyTo,
-      new MailPoetMapper(),
+      $this->diContainer->get(MailPoetMapper::class),
       $this->makeEmpty(AuthorizedEmailsController::class, ['checkAuthorizedEmailAddresses' => Expected::once()])
     );
     $mailer->api = $this->makeEmpty(
@@ -295,7 +295,7 @@ class MailPoetAPITest extends \MailPoetTest {
       $this->mailer,
       [
         'blacklist' => $blacklist,
-        'errorMapper' => new MailPoetMapper(),
+        'errorMapper' => $this->diContainer->get(MailPoetMapper::class),
         'servicesChecker' => Stub::make(
           new ServicesChecker(),
           ['isMailPoetAPIKeyValid' => true],
@@ -321,7 +321,7 @@ class MailPoetAPITest extends \MailPoetTest {
       $this->mailer,
       [
         'blacklist' => $blacklist,
-        'errorMapper' => new MailPoetMapper(),
+        'errorMapper' => $this->diContainer->get(MailPoetMapper::class),
         'servicesChecker' => Stub::make(
           new ServicesChecker(),
           ['isMailPoetAPIKeyValid' => true],
diff --git a/mailpoet/tests/unit/Mailer/Methods/ErrorMappers/MailPoetMapperTest.php b/mailpoet/tests/unit/Mailer/Methods/ErrorMappers/MailPoetMapperTest.php
index 7d71b61811..f7811dc757 100644
--- a/mailpoet/tests/unit/Mailer/Methods/ErrorMappers/MailPoetMapperTest.php
+++ b/mailpoet/tests/unit/Mailer/Methods/ErrorMappers/MailPoetMapperTest.php
@@ -3,9 +3,13 @@
 namespace MailPoet\Test\Mailer\Methods\ErrorMappers;
 
 use Codeception\Stub;
+use MailPoet\Config\ServicesChecker;
 use MailPoet\Mailer\MailerError;
 use MailPoet\Mailer\Methods\ErrorMappers\MailPoetMapper;
+use MailPoet\Services\Bridge;
 use MailPoet\Services\Bridge\API;
+use MailPoet\Settings\SettingsController;
+use MailPoet\Util\License\Features\Subscribers;
 use MailPoet\WP\Functions as WPFunctions;
 
 class MailPoetMapperTest extends \MailPoetUnitTest {
@@ -17,16 +21,22 @@ class MailPoetMapperTest extends \MailPoetUnitTest {
 
   public function _before() {
     parent::_before();
-    $this->mapper = new MailPoetMapper();
-    $this->subscribers = ['a@example.com', 'c d <b@example.com>'];
-    WPFunctions::set(Stub::make(new WPFunctions, [
+    $wpFunctions = Stub::make(new WPFunctions, [
       '_x' => function ($value) {
         return $value;
       },
       'escAttr' => function ($value) {
         return $value;
       },
-    ]));
+    ]);
+    $this->mapper = new MailPoetMapper(
+      Stub::make(Bridge::class),
+      Stub::make(ServicesChecker::class),
+      Stub::make(SettingsController::class),
+      Stub::make(Subscribers::class),
+      $wpFunctions
+    );
+    $this->subscribers = ['a@example.com', 'c d <b@example.com>'];
   }
 
   public function testCreateBlacklistError() {