diff --git a/core/lib/Drupal/Core/CoreServiceProvider.php b/core/lib/Drupal/Core/CoreServiceProvider.php
index c9eea1f..4a3d748 100644
--- a/core/lib/Drupal/Core/CoreServiceProvider.php
+++ b/core/lib/Drupal/Core/CoreServiceProvider.php
@@ -136,7 +136,7 @@ protected function registerTest(ContainerBuilder $container) {
     }
     // Add the HTTP request middleware to Guzzle.
     $container
-      ->register('test.http_client.handler', 'Drupal\Core\Test\EventSubscriber\HttpRequestSubscriber')
+      ->register('test.http_client.middleware', 'Drupal\Core\Test\EventSubscriber\TestHttpClientMiddleware')
       ->addTag('http_client_middleware');
   }
 
diff --git a/core/modules/aggregator/src/Plugin/aggregator/fetcher/DefaultFetcher.php b/core/modules/aggregator/src/Plugin/aggregator/fetcher/DefaultFetcher.php
index 1a7870c..c9e6f92 100644
--- a/core/modules/aggregator/src/Plugin/aggregator/fetcher/DefaultFetcher.php
+++ b/core/modules/aggregator/src/Plugin/aggregator/fetcher/DefaultFetcher.php
@@ -91,8 +91,9 @@ public function fetch(FeedInterface $feed) {
       $actual_uri = NULL;
       $response = $this->httpClientFactory->fromOptions(['allow_redirects' => [
         'on_redirect' => function(RequestInterface $request, ResponseInterface $response, UriInterface $uri) use (&$actual_uri) {
-        $actual_uri = (string) $uri;
-      }]])->send($request);
+          $actual_uri = (string) $uri;
+        }
+      ]])->send($request);
 
       // In case of a 304 Not Modified, there is no new content, so return
       // FALSE.
diff --git a/core/modules/locale/locale.batch.inc b/core/modules/locale/locale.batch.inc
index c43508c..4b67ddb 100644
--- a/core/modules/locale/locale.batch.inc
+++ b/core/modules/locale/locale.batch.inc
@@ -240,8 +240,9 @@ function locale_translation_http_check($uri) {
     $actual_uri = NULL;
     $response = \Drupal::service('http_client_factory')->fromOptions(['allow_redirects' => [
       'on_redirect' => function(RequestInterface $request, ResponseInterface $response, UriInterface $request_uri) use (&$actual_uri) {
-      $actual_uri = (string) $request_uri;
-    }]])->head($uri);
+        $actual_uri = (string) $request_uri;
+      }
+    ]])->head($uri);
     $result = array();
 
     // Return the effective URL if it differs from the requested.
diff --git a/core/modules/simpletest/src/Tests/SimpleTestTest.php b/core/modules/simpletest/src/Tests/SimpleTestTest.php
index e4df908..540a838 100644
--- a/core/modules/simpletest/src/Tests/SimpleTestTest.php
+++ b/core/modules/simpletest/src/Tests/SimpleTestTest.php
@@ -157,7 +157,7 @@ function stubTest() {
     // request. This allows the stub test to make requests. The event does not
     // fire here and drupal_generate_test_ua() can not generate a key for a
     // test in a test since the prefix has changed.
-    // @see \Drupal\Core\Test\EventSubscriber\HttpRequestSubscriber::onBeforeSendRequest()
+    // @see \Drupal\Core\Test\EventSubscriber\TestHttpClientMiddleware::onBeforeSendRequest()
     // @see drupal_generate_test_ua();
     $key_file = DRUPAL_ROOT . '/sites/simpletest/' . substr($this->databasePrefix, 10) . '/.htkey';
     $private_key = Crypt::randomBytesBase64(55);