diff --git a/core/tests/Drupal/Tests/KernelTestBase.php b/core/tests/Drupal/Tests/KernelTestBase.php
index 5ca8357..d59d331 100644
--- a/core/tests/Drupal/Tests/KernelTestBase.php
+++ b/core/tests/Drupal/Tests/KernelTestBase.php
@@ -70,6 +70,11 @@
   protected $backupGlobals = TRUE;
 
   /**
+   * {@inheritdoc}
+   */
+  protected $runTestInSeparateProcess = TRUE;
+
+  /**
    * Flag to reset all static class properties between tests.
    *
    * @var bool