diff --git a/lib/Models/ScheduledTask.php b/lib/Models/ScheduledTask.php
index 9a1eebe7e1..d2e26f73aa 100644
--- a/lib/Models/ScheduledTask.php
+++ b/lib/Models/ScheduledTask.php
@@ -36,7 +36,7 @@ class ScheduledTask extends Model {
 
   public function __construct() {
     parent::__construct();
-    $this->wp = new WPFunctions();
+    $this->wp = WPFunctions::get();
   }
 
   public function subscribers() {
diff --git a/tests/integration/AutomaticEmails/WooCommerce/Events/AbandonedCartTest.php b/tests/integration/AutomaticEmails/WooCommerce/Events/AbandonedCartTest.php
index a56d54e807..467aa0b389 100644
--- a/tests/integration/AutomaticEmails/WooCommerce/Events/AbandonedCartTest.php
+++ b/tests/integration/AutomaticEmails/WooCommerce/Events/AbandonedCartTest.php
@@ -50,7 +50,13 @@ class AbandonedCartTest extends \MailPoetTest {
     Carbon::setTestNow($this->currentTime);
 
     $this->wp = $this->makeEmpty(WPFunctions::class, [
-      'currentTime' => $this->currentTime->getTimestamp(),
+      'currentTime' => function ($arg) {
+        if ($arg === 'timestamp') {
+          return $this->currentTime->getTimestamp();
+        } elseif ($arg === 'mysql') {
+          return $this->currentTime->format('Y-m-d H:i:s');
+        }
+      },
     ]);
     WPFunctions::set($this->wp);
 
diff --git a/tests/integration/Cron/Workers/SchedulerTest.php b/tests/integration/Cron/Workers/SchedulerTest.php
index a427ba7483..62ed056012 100644
--- a/tests/integration/Cron/Workers/SchedulerTest.php
+++ b/tests/integration/Cron/Workers/SchedulerTest.php
@@ -317,8 +317,14 @@ class SchedulerTest extends \MailPoetTest {
   }
 
   public function testItReschedulesQueueDeliveryWhenMailpoetSubscriberHasNotConfirmedSubscription() {
-    $currentTime = Carbon::createFromTimestamp(WPFunctions::get()->currentTime('timestamp'));
+    $timestamp = WPFunctions::get()->currentTime('timestamp');
+    $wpFunctions = $this->make(WPFunctions::class, [
+      'currentTime' => $timestamp,
+    ]);
+    WPFunctions::set($wpFunctions);
+    $currentTime = Carbon::createFromTimestamp($timestamp);
     Carbon::setTestNow($currentTime); // mock carbon to return current time
+
     $subscriber = $this->_createSubscriber($wpUserId = null, 'unconfirmed');
     $segment = $this->_createSegment();
     $subscriberSegment = $this->_createSubscriberSegment($subscriber->id, $segment->id);
@@ -344,6 +350,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(Carbon::parse($updatedQueue->scheduledAt))->equals(
       $currentTime->addMinutes(ScheduledTask::BASIC_RESCHEDULE_TIMEOUT)
     );
+    WPFunctions::set(new WPFunctions());
   }
 
   public function testItDoesntRunQueueDeliveryWhenMailpoetSubscriberHasUnsubscribed() {