diff --git a/zecsy.hpp b/zecsy.hpp
index 377d8e7..82a38fc 100644
--- a/zecsy.hpp
+++ b/zecsy.hpp
@@ -114,8 +114,8 @@ namespace zecsy
         template<typename... T>
         void remove(entity_id e);
 
-        template<typename... T, typename Callable>
-        void query(Callable&& system);
+        template<typename... T>
+        void query(auto&& system);
     private:
         entities_set alive_entities;
         entity_id entity_counter = 0;
@@ -278,8 +278,8 @@ namespace zecsy
         (remove<Rest>(e), ...);
     }
 
-    template<typename... T, typename Callable>
-    inline void world::query(Callable&& system)
+    template<typename... T>
+    inline void world::query(auto&& system)
     {
         for(auto e: alive_entities)
         {