diff --git a/apps/emqx/test/emqx_cth_cluster.erl b/apps/emqx/test/emqx_cth_cluster.erl
index 194a681d5..9ad8dc0f4 100644
--- a/apps/emqx/test/emqx_cth_cluster.erl
+++ b/apps/emqx/test/emqx_cth_cluster.erl
@@ -238,6 +238,8 @@ default_appspec(emqx_conf, Spec, _NodeSpecs) ->
             listeners => allocate_listener_ports([tcp, ssl, ws, wss], Spec)
         }
     };
+default_appspec(emqx, Spec, _NodeSpecs) ->
+    #{config => #{listeners => allocate_listener_ports([tcp, ssl, ws, wss], Spec)}};
 default_appspec(_App, _, _) ->
     #{}.