diff --git a/core/core.services.yml b/core/core.services.yml
index b333112..e87f0a7 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -254,7 +254,7 @@ services:
     class: Drupal\Core\Routing\RouteProvider
     arguments: ['@database']
   router.route_preloader:
-    class: Drupal\Core\Routing\AdminRoutesPreloader
+    class: Drupal\Core\Routing\NonAdminRoutesPreloader
     arguments: ['@router.route_provider', '@state', '@content_negotiation']
     tags:
       - { name: 'event_subscriber' }
diff --git a/core/lib/Drupal/Core/Routing/NonAdminRoutesPreloader.php b/core/lib/Drupal/Core/Routing/NonAdminRoutesPreloader.php
index dc810c7..4275832 100644
--- a/core/lib/Drupal/Core/Routing/NonAdminRoutesPreloader.php
+++ b/core/lib/Drupal/Core/Routing/NonAdminRoutesPreloader.php
@@ -8,14 +8,13 @@
 namespace Drupal\Core\Routing;
 
 use Drupal\Core\ContentNegotiation;
-use Drupal\Core\DestructableInterface;
 use Drupal\Core\KeyValueStore\KeyValueStoreInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\HttpKernel\Event\KernelEvent;
 use Symfony\Component\HttpKernel\KernelEvents;
 
 /**
- * Defines a class which preloads admin routes.
+ * Defines a class which preloads non admin routes.
  */
 class NonAdminRoutesPreloader implements EventSubscriberInterface {
 
@@ -89,7 +88,10 @@ protected function getAdminRoutes() {
    *   The Event to process.
    */
   public function onRequest(KernelEvent $event) {
-    $this->loadAdminRoutes();
+    // Just preload on normal html pages, as they will contain the menu links.
+    if ($this->negotiation->getContentType($event->getRequest()) == 'html') {
+      $this->loadAdminRoutes();
+    }
   }
 
   /**
@@ -112,7 +114,7 @@ public function onAlterRoutes(RouteBuildEvent $event) {
     foreach ($collection->all() as $name => $route) {
       // Just preload non admin and _content routes, as they are the ones
       // that appear on menu links and co.
-      if (strpos($route->getPath(), '/admin') !== 0 && $route->hasDefault('_content')) {
+      if (strpos($route->getPath(), '/admin') === FALSE && $route->hasDefault('_content')) {
         $this->adminRoutesOnRebuild[] = $name;
       }
     }