diff --git a/core/modules/system/lib/Drupal/system/Controller/ThemeController.php b/core/modules/system/lib/Drupal/system/Controller/ThemeController.php
index 9baaf48..4b95c00 100644
--- a/core/modules/system/lib/Drupal/system/Controller/ThemeController.php
+++ b/core/modules/system/lib/Drupal/system/Controller/ThemeController.php
@@ -9,9 +9,10 @@
 
 use Drupal\Core\Controller\ControllerBase;
 use Drupal\Core\Extension\ThemeHandlerInterface;
+use Drupal\Core\Routing\RouteBuilderInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
-use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
  * Controller for theme handling.
@@ -26,13 +27,23 @@ class ThemeController extends ControllerBase {
   protected $themeHandler;
 
   /**
+   * The route builder service.
+   *
+   * @var \Drupal\Core\Routing\RouteBuilderInterface
+   */
+  protected $routeBuilder;
+
+  /**
    * Constructs a new ThemeController.
    *
    * @param \Drupal\Core\Extension\ThemeHandlerInterface $theme_handler
    *   The theme handler.
+   * @param \Drupal\Core\Routing\RouteBuilderInterface $route_builder
+   *   The route builder.
    */
-  public function __construct(ThemeHandlerInterface $theme_handler) {
+  public function __construct(ThemeHandlerInterface $theme_handler, RouteBuilderInterface $route_builder) {
     $this->themeHandler = $theme_handler;
+    $this->routeBuilder = $route_builder;
   }
 
   /**
@@ -40,7 +51,8 @@ public function __construct(ThemeHandlerInterface $theme_handler) {
    */
   public static function create(ContainerInterface $container) {
     return new static(
-      $container->get('theme_handler')
+      $container->get('theme_handler'),
+      $container->get('route.builder')
     );
   }
 
@@ -151,7 +163,7 @@ public function setDefaultTheme(Request $request) {
         // Set the default theme.
         $config->set('default', $theme)->save();
 
-        \Drupal::service('router.builder')->setRebuildNeeded();
+        $this->routeBuilder->setRebuildNeeded();
 
         // The status message depends on whether an admin theme is currently in
         // use: a value of 0 means the admin theme is set to be the default