diff --git a/src/Server/WebSocket/Middleware/HandShakeMiddleware.php b/src/Server/WebSocket/Middleware/HandShakeMiddleware.php
index bd7c3a46c1..1f28392335 100644
--- a/src/Server/WebSocket/Middleware/HandShakeMiddleware.php
+++ b/src/Server/WebSocket/Middleware/HandShakeMiddleware.php
@@ -26,7 +26,7 @@ public function process(ServerRequestInterface $request, RequestHandlerInterface
         {
             /** @var \Imi\Server\Http\Route\RouteResult $routeResult */
             $routeResult = RequestContext::get('routeResult');
-            if($routeResult->routeItem->wsConfig->wsOnly)
+            if($routeResult->routeItem->wsConfig->wsOnly ?? false)
             {
                 $response = $response->withStatus(StatusCode::BAD_REQUEST);
             }