diff --git a/src/Illuminate/Routing/Router.php b/src/Illuminate/Routing/Router.php
index 2be5d05e3a14..379dcdd3bd63 100644
--- a/src/Illuminate/Routing/Router.php
+++ b/src/Illuminate/Routing/Router.php
@@ -709,7 +709,7 @@ protected function mergeGroupAttributesIntoRoute($route)
     {
         $route->setAction($this->mergeWithLastGroup(
             $route->getAction(),
-            $prependExistingPrefix = false
+            prependExistingPrefix: false
         ));
     }