diff --git a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
index 61c54d1..2565b56 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
@@ -808,6 +808,10 @@ protected function setUp() {
     // Execute the non-interactive installer.
     require_once DRUPAL_ROOT . '/core/includes/install.core.inc';
     install_drupal($parameters);
+    if (file_exists(DRUPAL_ROOT . '/sites/default/settings.testing.php')) {
+      copy(DRUPAL_ROOT . '/sites/default/settings.testing.php', DRUPAL_ROOT . '/' . $this->siteDirectory . '/settings.testing.php');
+      file_put_contents(DRUPAL_ROOT . '/' . $this->siteDirectory . '/settings.php', "\n" . 'include DRUPAL_ROOT . \'/\' . $conf_path . \'/settings.testing.php\';' ."\n", FILE_APPEND);
+    }
 
     // Import new settings.php written by the installer.
     drupal_settings_initialize();