diff --git a/libraries/src/Router/SiteRouter.php b/libraries/src/Router/SiteRouter.php
index 601d3069db26f..921b8ae56052b 100644
--- a/libraries/src/Router/SiteRouter.php
+++ b/libraries/src/Router/SiteRouter.php
@@ -588,9 +588,7 @@ public function getComponentRouter($component)
      */
     public function setComponentRouter($component, $router)
     {
-        $reflection = new \ReflectionClass($router);
-
-        if (\in_array('Joomla\\CMS\\Component\\Router\\RouterInterface', $reflection->getInterfaceNames())) {
+        if ($router instanceof RouterInterface) {
             $this->componentRouters[$component] = $router;
 
             return true;