diff --git a/src/GroupRuleInterface.php b/src/GroupRuleInterface.php
index ffd0c48..90049ec 100644
--- a/src/GroupRuleInterface.php
+++ b/src/GroupRuleInterface.php
@@ -18,7 +18,7 @@ public function routePrefix($routePrefix);
      * @param array $middleware
      * @return GroupRuleInterface
      */
-    public function middleware(array $middleware);
+    public function middleware($middleware);
 
     /**
      * @param $domain