diff --git a/crow/include/crow/routing.h b/crow/include/crow/routing.h
index 0fe692e..f3fedd8 100644
--- a/crow/include/crow/routing.h
+++ b/crow/include/crow/routing.h
@@ -910,7 +910,7 @@
 
     if (!rule_index) {
       CROW_LOG_DEBUG << "Cannot match rules " << req.url;
-      res = response(boost::beast::http::status::not_found);
+      res.result(boost::beast::http::status::not_found);
       res.end();
       return;
     }