diff --git a/core/modules/locale/tests/modules/locale_test/lib/Drupal/locale_test/LocaleTestBundle.php b/core/modules/locale/tests/modules/locale_test/lib/Drupal/locale_test/LocaleTestBundle.php
index 2f9db4a..c1035ec 100644
--- a/core/modules/locale/tests/modules/locale_test/lib/Drupal/locale_test/LocaleTestBundle.php
+++ b/core/modules/locale/tests/modules/locale_test/lib/Drupal/locale_test/LocaleTestBundle.php
@@ -14,7 +14,6 @@
 
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\HttpKernel\Bundle\Bundle;
-use Symfony\Component\DependencyInjection\Reference;
 
 /**
  * Locale Test dependency injection container.
@@ -26,9 +25,7 @@ class LocaleTestBundle extends Bundle {
    */
   public function build(ContainerBuilder $container) {
     // Register our response subscriber to handle finished responses.
-    $container->register('finish_response_subscriber', 'Drupal\locale_test\LocaleTestFinishResponseSubscriber')
-      ->addArgument(new Reference('language_manager'))
-      ->setScope('request')
+    $container->register('locale_test_finish_response_subscriber', 'Drupal\locale_test\LocaleTestFinishResponseSubscriber')
       ->addTag('event_subscriber');
   }
 }
diff --git a/core/modules/locale/tests/modules/locale_test/lib/Drupal/locale_test/LocaleTestFinishResponseSubscriber.php b/core/modules/locale/tests/modules/locale_test/lib/Drupal/locale_test/LocaleTestFinishResponseSubscriber.php
index e62705e..d93ac89 100644
--- a/core/modules/locale/tests/modules/locale_test/lib/Drupal/locale_test/LocaleTestFinishResponseSubscriber.php
+++ b/core/modules/locale/tests/modules/locale_test/lib/Drupal/locale_test/LocaleTestFinishResponseSubscriber.php
@@ -8,34 +8,51 @@
  * override the already configured 'Last-Modified' HTTP header which is set and
  * needed when a remote translation file is served via a menu callback. So this
  * is a new event subscriber which saves the value and sets it back.
+ * It does so with the saveLastModified() method which has a very high priority,
+ * so it can save the defined header really early in a class property. Then
+ * later on the setLastModified() method can set the header again using the
+ * value from this property, since it has a very low priority, it can manipulate
+ * the header after FinishResponseSubscriber has done its changes.
  */
 
 namespace Drupal\locale_test;
 
-use Drupal\Core\EventSubscriber\FinishResponseSubscriber;
-use Drupal\Core\Language\LanguageManager;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
 use Symfony\Component\HttpKernel\KernelEvents;
-use Symfony\Component\HttpKernel\HttpKernelInterface;
-use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
 /**
  * Response subscriber to handle finished responses.
  */
-class LocaleTestFinishResponseSubscriber extends FinishResponseSubscriber {
+class LocaleTestFinishResponseSubscriber implements EventSubscriberInterface {
+
+  public $lastModified;
+
+  /**
+   * Registers the methods in this class that should be listeners.
+   *
+   * @return array
+   *   An array of event listener definitions.
+   */
+  public static function getSubscribedEvents() {
+    $events[KernelEvents::RESPONSE][] = array('saveLastModified', 100);
+    $events[KernelEvents::RESPONSE][] = array('setLastModified', -100);
+    return $events;
+  }
+
+  /**
+   * Saves the 'Last-Modified' HTTP header in a class property.
+   */
+  public function saveLastModified(FilterResponseEvent $event) {
+    $this->lastModified = $event->getResponse()->headers->get('Last-Modified');
+  }
 
   /**
-   * Overrides Drupal\Core\EventSubscriber\FinishResponseSubscriber:onRespond().
+   * Sets the 'Last-Modified' HTTP header to the response.
    */
-  public function onRespond(FilterResponseEvent $event) {
-    // Save the 'Last-Modified' HTTP header's value.
-    $response = $event->getResponse();
-    $last_modified = $response->headers->get('Last-Modified');
-    // Parent method will change it to REQUEST_TIME.
-    parent::onRespond($event);
-    if (!empty($last_modified)) {
-      // But here it's the desired one again.
-      $response->headers->set('Last-Modified', $last_modified);
+  public function setLastModified(FilterResponseEvent $event) {
+    if (!empty($this->lastModified)) {
+      $event->getResponse()->headers->set('Last-Modified', $this->lastModified);
     }
   }
 }