diff --git a/core/tests/Drupal/FunctionalTests/Installer/InstallerTestBase.php b/core/tests/Drupal/FunctionalTests/Installer/InstallerTestBase.php
index 4168809baf..c396991a43 100644
--- a/core/tests/Drupal/FunctionalTests/Installer/InstallerTestBase.php
+++ b/core/tests/Drupal/FunctionalTests/Installer/InstallerTestBase.php
@@ -139,7 +139,8 @@ protected function setUp() {
       ->register('http_client_factory', 'Drupal\Core\Http\ClientFactory')
       ->setArguments([new Reference('http_handler_stack')]);
     $handler_stack = HandlerStack::create();
-    $handler_stack->push((new TestHttpClientMiddleware())(), 'test.http_client.middleware');
+    $middleware = new TestHttpClientMiddleware();
+    $handler_stack->push($middleware(), 'test.http_client.middleware');
     $this->container
       ->set('http_handler_stack', $handler_stack);