diff --git a/nixos/tests/upnp.nix b/nixos/tests/upnp.nix
index a7d837ea070..046c0a56b2a 100644
--- a/nixos/tests/upnp.nix
+++ b/nixos/tests/upnp.nix
@@ -90,7 +90,7 @@ in
       client1.succeed("upnpc -a ${internalClient1Address} 9000 9000 TCP")
 
       client1.wait_for_unit("httpd")
-      client2.wait_until_succeeds("curl http://${externalRouterAddress}:9000/")
+      client2.wait_until_succeeds("curl -f http://${externalRouterAddress}:9000/")
     '';
 
 })