diff --git a/core/modules/simpletest/lib/Drupal/simpletest/Tests/SimpleTestTest.php b/core/modules/simpletest/lib/Drupal/simpletest/Tests/SimpleTestTest.php
index 83f1048..f2a48f3 100755
--- a/core/modules/simpletest/lib/Drupal/simpletest/Tests/SimpleTestTest.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/Tests/SimpleTestTest.php
@@ -41,6 +41,7 @@ public static function getInfo() {
 
   function setUp() {
     if (!$this->isInChildSite()) {
+      file_put_contents($this->siteDirectory. '/' . 'settings.testing.php', '<?php if (!function_exists("simpletest_test_stub_settings_function")) {function simpletest_test_stub_settings_function() {}}');
       parent::setUp();
       // Create and log in an admin user.
       $this->drupalLogin($this->drupalCreateUser(array('administer unit tests')));
@@ -188,6 +189,11 @@ function stubTest() {
     $this->drupalCreateUser(array($this->invalid_permission));
 
     $this->pass(t('Test ID is @id.', array('@id' => $this->testId)));
+    // These two are tested by asserting the right number of passes and
+    // failures.
+    $this->assertTrue(file_exists(conf_path() . '/settings.testing.php'));
+    // Check the settings.testing.php file got included.
+    $this->assertTrue(function_exists('simpletest_test_stub_settings_function'));
 
     // Call trigger_error() without the required argument to trigger an E_WARNING.
     trigger_error();
@@ -234,7 +240,7 @@ function confirmStubTestResults() {
 
     $this->assertAssertion("Debug: 'Foo'", 'Debug', 'Fail', 'SimpleTestTest.php', 'Drupal\simpletest\Tests\SimpleTestTest->stubTest()');
 
-    $this->assertEqual('6 passes, 5 fails, 2 exceptions, 1 debug message', $this->childTestResults['summary']);
+    $this->assertEqual('8 passes, 5 fails, 2 exceptions, 1 debug message', $this->childTestResults['summary']);
 
     $this->test_ids[] = $test_id = $this->getTestIdFromResults();
     $this->assertTrue($test_id, 'Found test ID in results.');
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
index 1a37920..7bf2ee7 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
@@ -818,7 +818,8 @@ protected function setUp() {
     // Copy and prepare an actual settings.php, so as to resemble a regular
     // installation.
     // Not using File API; a potential error must trigger a PHP warning.
-    copy(DRUPAL_ROOT . '/sites/default/default.settings.php', DRUPAL_ROOT . '/' . $this->siteDirectory . '/settings.php');
+    $directory = DRUPAL_ROOT . '/' . $this->siteDirectory;
+    copy(DRUPAL_ROOT . '/sites/default/default.settings.php', $directory . '/settings.php');
 
     // All file system paths are created by System module during installation.
     // @see system_requirements()
@@ -842,6 +843,14 @@ protected function setUp() {
       'required' => TRUE,
     );
     $this->writeSettings($settings);
+    $settings_testing_file = DRUPAL_ROOT . '/' . $this->originalSite . '/settings.testing.php';
+    if (file_exists($settings_testing_file)) {
+      // Copy the testing specific overrides in place.
+      copy($settings_testing_file, $directory . '/settings.testing.php');
+      // Add the name of the testing class to settings.php and include the
+      // testing specific overrides
+      file_put_contents($directory . '/settings.php', "\n\$test_class = '" . get_class($this) ."';\n" . 'include DRUPAL_ROOT . \'/\' . $conf_path . \'/settings.testing.php\';' ."\n", FILE_APPEND);
+    }
 
     // Since Drupal is bootstrapped already, install_begin_request() will not
     // bootstrap into DRUPAL_BOOTSTRAP_CONFIGURATION (again). Hence, we have to
@@ -864,7 +873,7 @@ protected function setUp() {
     // directory has to be writable.
     // TestBase::restoreEnvironment() will delete the entire site directory.
     // Not using File API; a potential error must trigger a PHP warning.
-    chmod(DRUPAL_ROOT . '/' . $this->siteDirectory, 0777);
+    chmod($directory, 0777);
 
     $this->rebuildContainer();