diff --git a/src/Middleware/AddHttp2ServerPush.php b/src/Middleware/AddHttp2ServerPush.php
index 2be6464..b0882e7 100644
--- a/src/Middleware/AddHttp2ServerPush.php
+++ b/src/Middleware/AddHttp2ServerPush.php
@@ -29,7 +29,7 @@ public function handle(Request $request, Closure $next)
     {
         $response = $next($request);
 
-        if ($response->isRedirection()) {
+        if ($response->isRedirection() || !$response instanceof Response) {
             return $response;
         }