diff --git a/mailpoet/tests/integration/_bootstrap.php b/mailpoet/tests/integration/_bootstrap.php
index 6c247ab793..87ee88bf07 100644
--- a/mailpoet/tests/integration/_bootstrap.php
+++ b/mailpoet/tests/integration/_bootstrap.php
@@ -82,6 +82,8 @@ abstract class MailPoetTest extends \Codeception\TestCase\Test { // phpcs:ignore
 
   protected static $savedGlobals;
 
+  protected $tester;
+
   /** @var ContainerWrapper */
   protected $diContainer;