diff --git a/core/lib/Drupal/Core/EventSubscriber/RouteNormalizerRequestSubscriber.php b/core/lib/Drupal/Core/EventSubscriber/RouteNormalizerRequestSubscriber.php
index 129d515..e63162b 100644
--- a/core/lib/Drupal/Core/EventSubscriber/RouteNormalizerRequestSubscriber.php
+++ b/core/lib/Drupal/Core/EventSubscriber/RouteNormalizerRequestSubscriber.php
@@ -91,7 +91,7 @@ public function onKernelRequestRedirect(GetResponseEvent $event) {
       $redirect_uri = $this->urlGenerator->generateFromRoute($route_name, [], $options);
       $original_uri = $request->getSchemeAndHttpHost() . $request->getRequestUri();
       if ($redirect_uri != $original_uri) {
-        $response = new RedirectResponse($redirect_uri);
+        $response = new RedirectResponse($redirect_uri, 301);
         $response->headers->set('X-Drupal-Route-Normalizer', 1);
         $event->setResponse($response);
       }