diff --git a/src/Router.php b/src/Router.php
index 66aa5db..402a4a4 100755
--- a/src/Router.php
+++ b/src/Router.php
@@ -58,7 +58,7 @@ class Router
      * @param RouteCollection    $collection
      * @param ContainerInterface $container
      */
-    public function __construct(RouteCollection $collection, ContainerInterface $container)
+    public function __construct(RouteCollection $collection, ContainerInterface $container = null)
     {
         $this->routes = $collection;