diff --git a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
index da6a65f3a5b..e483a0b456a 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
@@ -161,6 +161,13 @@ abstract class TestBase {
    */
   public $dieOnFail = FALSE;
 
+  /**
+   * The dependency injection container used in the test.
+   *
+   * @var \Symfony\Component\DependencyInjection\ContainerInterface
+   */
+  protected $container;
+
   /**
    * Constructor for Test.
    *