diff --git a/core/modules/media/media.post_update.php b/core/modules/media/media.post_update.php
index fca9fbc82e..e7bfc4d131 100644
--- a/core/modules/media/media.post_update.php
+++ b/core/modules/media/media.post_update.php
@@ -20,7 +20,7 @@ function media_post_update_storage_handler() {
 }
 
 /**
- * Keeps the standalone URL for Media entities enabled on existing sites.
+ * Keep media entities viewable at media/{id}.
  */
 function media_post_update_enable_standalone_url() {
   \Drupal::configFactory()
diff --git a/core/modules/media/tests/src/Functional/Rest/MediaResourceTestBase.php b/core/modules/media/tests/src/Functional/Rest/MediaResourceTestBase.php
index 05e8503cc5..78678e2772 100644
--- a/core/modules/media/tests/src/Functional/Rest/MediaResourceTestBase.php
+++ b/core/modules/media/tests/src/Functional/Rest/MediaResourceTestBase.php
@@ -53,9 +53,6 @@ public function setUp() {
       ->save(TRUE);
 
     $this->container->get('router.builder')->rebuild();
-
-    $this->serializer = $this->container->get('serializer');
-    $this->resourceConfigStorage = $this->container->get('entity_type.manager')->getStorage('rest_resource_config');
   }
 
   /**
diff --git a/core/modules/media/tests/src/Functional/Update/MediaUpdateTest.php b/core/modules/media/tests/src/Functional/Update/MediaUpdateTest.php
index ea91915b0c..306cb81007 100644
--- a/core/modules/media/tests/src/Functional/Update/MediaUpdateTest.php
+++ b/core/modules/media/tests/src/Functional/Update/MediaUpdateTest.php
@@ -3,6 +3,8 @@
 namespace Drupal\Tests\media\Functional\Update;
 
 use Drupal\FunctionalTests\Update\UpdatePathTestBase;
+use Drupal\media\Entity\Media;
+use Drupal\Tests\media\Traits\MediaTypeCreationTrait;
 use Drupal\user\Entity\Role;
 
 /**
@@ -13,6 +15,8 @@
  */
 class MediaUpdateTest extends UpdatePathTestBase {
 
+  use MediaTypeCreationTrait;
+
   /**
    * {@inheritdoc}
    */
@@ -80,4 +84,34 @@ public function testOwnerEntityKey() {
     $this->assertEquals('uid', $entity_type->getKey('owner'));
   }
 
+  /**
+   * Tests that the standalone URL is still accessible.
+   *
+   * @see media_post_update_enable_standalone_url()
+   */
+  public function testEnableStandaloneUrl() {
+    $this->container->get('module_installer')->install(['media_test_source']);
+
+    // Create a media type.
+    $mediaType = $this->createMediaType('test');
+
+    // Run updates.
+    $this->runUpdates();
+
+    // Create a media item.
+    $media = Media::create([
+      'bundle' => $mediaType->id(),
+      'name' => 'Unnamed',
+    ]);
+    $media->save();
+
+    $user = $this->drupalCreateUser([
+      'administer media',
+    ]);
+    $this->drupalLogin($user);
+
+    $this->drupalGet('media/' . $media->id());
+    $this->assertSession()->statusCodeEquals(200);
+  }
+
 }