diff --git a/core/modules/field_ui/src/Tests/ManageFieldsTest.php b/core/modules/field_ui/src/Tests/ManageFieldsTest.php
index ce8e592..2255f29 100644
--- a/core/modules/field_ui/src/Tests/ManageFieldsTest.php
+++ b/core/modules/field_ui/src/Tests/ManageFieldsTest.php
@@ -626,7 +626,7 @@ public function testExternalDestinations() {
     $this->drupalPostForm('admin/structure/types/manage/article/fields/node.article.body/storage', [], 'Save field settings', $options);
     // The external redirect should not fire.
     $this->assertUrl('admin/structure/types/manage/article/fields/node.article.body/storage', $options);
-    $this->assertResponse(500);
+    $this->assertResponse(400);
   }
 
   /**
diff --git a/core/tests/Drupal/Tests/Core/EventSubscriber/RedirectResponseSubscriberTest.php b/core/tests/Drupal/Tests/Core/EventSubscriber/RedirectResponseSubscriberTest.php
index 49610ec..c4bef68 100644
--- a/core/tests/Drupal/Tests/Core/EventSubscriber/RedirectResponseSubscriberTest.php
+++ b/core/tests/Drupal/Tests/Core/EventSubscriber/RedirectResponseSubscriberTest.php
@@ -148,6 +148,9 @@ public function testDestinationRedirectToExternalUrl($request, $expected) {
     }
   }
 
+  /**
+   * @covers ::checkRedirectUrl
+   */
   public function testRedirectWithOptInExternalUrl() {
     $dispatcher = new EventDispatcher();
     $kernel = $this->getMock('Symfony\Component\HttpKernel\HttpKernelInterface');