diff --git a/core/lib/Drupal/Core/Controller/ControllerResolver.php b/core/lib/Drupal/Core/Controller/ControllerResolver.php
index b0b9b38..5c3537a 100644
--- a/core/lib/Drupal/Core/Controller/ControllerResolver.php
+++ b/core/lib/Drupal/Core/Controller/ControllerResolver.php
@@ -104,6 +104,10 @@ protected function createController($controller) {
    */
   protected function doGetArguments(Request $request, $controller, array $parameters) {
     $arguments = parent::doGetArguments($request, $controller, $parameters);
+    if (!$request->attributes->has('converted')) {
+      return $arguments;
+    }
+
     $converted = $request->attributes->get('converted')->all();
     foreach ($parameters as $parameter) {
       // Use the converted/upcast value if a parameter has a typehint.