diff --git a/net/http/src/THttpServer.cxx b/net/http/src/THttpServer.cxx
index 74d6806332a24..446303fa63026 100644
--- a/net/http/src/THttpServer.cxx
+++ b/net/http/src/THttpServer.cxx
@@ -1305,8 +1305,10 @@ Bool_t THttpServer::ExecuteWS(std::shared_ptr<THttpCallArg> &arg, Bool_t externa
       return kTRUE;
    }
 
-   if (!handler)
+   if (!handler) {
+      arg->Set404();
       return kFALSE;
+   }
 
    Bool_t process = kFALSE;