diff --git a/core/lib/Drupal/Core/EventSubscriber/RedirectResponseSubscriber.php b/core/lib/Drupal/Core/EventSubscriber/RedirectResponseSubscriber.php
index f88272c..5a4265e 100644
--- a/core/lib/Drupal/Core/EventSubscriber/RedirectResponseSubscriber.php
+++ b/core/lib/Drupal/Core/EventSubscriber/RedirectResponseSubscriber.php
@@ -8,7 +8,7 @@
 namespace Drupal\Core\EventSubscriber;
 
 use Drupal\Component\Utility\UrlHelper;
-use Drupal\Core\Routing\RedirectResponseToExternalUrl;
+use Drupal\Core\Routing\RedirectResponseAllowExternalUrl;
 use Drupal\Core\Routing\RequestContext;
 use Drupal\Core\Routing\UrlGeneratorInterface;
 use InvalidArgumentException;
@@ -100,8 +100,8 @@ public function checkRedirectUrl(FilterResponseEvent $event) {
         // URL is not external. In case this is wanted, check for a custom flag
         // on RedirectResponse.
         $url = $response->getTargetUrl();
-        if (UrlHelper::isExternal($url) && !UrlHelper::externalIsLocal($url, $this->requestContext->getCompleteBaseUrl()) && !$response instanceof RedirectResponseToExternalUrl) {
-          $this->setBadRequestException($event, 'Redirects to external URLs are not allowed by default, use \Drupal\Core\Routing\RedirectResponseToExternalUrl for it');
+        if (!$response instanceof RedirectResponseAllowExternalUrl && UrlHelper::isExternal($url) && !UrlHelper::externalIsLocal($url, $this->requestContext->getCompleteBaseUrl())) {
+          $this->setBadRequestException($event, 'Redirects to external URLs are not allowed by default, use \Drupal\Core\Routing\RedirectResponseAllowExternalUrl for it');
         }
       }
       // Potentially thrown by UrlHelper::externalIsLocal().
diff --git a/core/lib/Drupal/Core/Routing/RedirectResponseToExternalUrl.php b/core/lib/Drupal/Core/Routing/RedirectResponseAllowExternalUrl.php
similarity index 51%
rename from core/lib/Drupal/Core/Routing/RedirectResponseToExternalUrl.php
rename to core/lib/Drupal/Core/Routing/RedirectResponseAllowExternalUrl.php
index a18e23f..4bbd94f 100644
--- a/core/lib/Drupal/Core/Routing/RedirectResponseToExternalUrl.php
+++ b/core/lib/Drupal/Core/Routing/RedirectResponseAllowExternalUrl.php
@@ -10,10 +10,13 @@
 use \Symfony\Component\HttpFoundation\RedirectResponse;
 
 /**
- * Overrides the symfony redirect response object to provide more security.
+ * Provides a redirect response which allows to redirect to an external URl.
+ *
+ * By default Drupal disables redirects to external URLs in order to provide
+ * better security.
  *
  * @see \Drupal\Core\EventSubscriber\RedirectResponseSubscriber::checkRedirectUrl
  */
-class RedirectResponseToExternalUrl extends RedirectResponse {
+class RedirectResponseAllowExternalUrl extends RedirectResponse {
 
 }
diff --git a/core/tests/Drupal/Tests/Core/EventSubscriber/RedirectResponseSubscriberTest.php b/core/tests/Drupal/Tests/Core/EventSubscriber/RedirectResponseSubscriberTest.php
index 57c95cb..3cf896e 100644
--- a/core/tests/Drupal/Tests/Core/EventSubscriber/RedirectResponseSubscriberTest.php
+++ b/core/tests/Drupal/Tests/Core/EventSubscriber/RedirectResponseSubscriberTest.php
@@ -8,7 +8,7 @@
 namespace Drupal\Tests\Core\EventSubscriber;
 
 use Drupal\Core\EventSubscriber\RedirectResponseSubscriber;
-use Drupal\Core\Routing\RedirectResponseToExternalUrl;
+use Drupal\Core\Routing\RedirectResponseAllowExternalUrl;
 use Drupal\Core\Routing\RequestContext;
 use Drupal\Tests\UnitTestCase;
 use Symfony\Component\EventDispatcher\EventDispatcher;
@@ -148,7 +148,7 @@ public function testDestinationRedirectToExternalUrl($request, $expected) {
   public function testRedirectWithOptInExternalUrl() {
     $dispatcher = new EventDispatcher();
     $kernel = $this->getMock('Symfony\Component\HttpKernel\HttpKernelInterface');
-    $response = new RedirectResponseToExternalUrl('http://external-url.com');
+    $response = new RedirectResponseAllowExternalUrl('http://external-url.com');
     $url_generator = $this->getMockBuilder('Drupal\Core\Routing\UrlGenerator')
       ->disableOriginalConstructor()
       ->setMethods(array('generateFromPath'))