diff --git a/cxx/mcc_fsm.h b/cxx/mcc_fsm.h
index a26a305..e43f2d9 100644
--- a/cxx/mcc_fsm.h
+++ b/cxx/mcc_fsm.h
@@ -328,11 +328,17 @@ protected:
     template <typename... TplTs>
     struct collect_states_t;
 
+    // template <typename TplT>
+    // struct collect_states_t<TplT> {
+    //     using states_t = TplT;
+    // };
+
     template <traits::fsm_state_c... StTs, typename... TplTs>
     struct collect_states_t<std::tuple<StTs...>, TplTs...> {
-        using states_t = merge_tuples_res_t<std::tuple<StTs...>,
-                                            collect_states_t<typename StTs::transition_t::unique_states_t...>,
-                                            TplTs...>;
+        using states_t =
+            merge_tuples_res_t<std::tuple<StTs...>,
+                               typename collect_states_t<typename StTs::transition_t::unique_states_t...>::states_t,
+                               TplTs...>;
     };