diff --git a/include/chaiscript/dispatchkit/proxy_functions_detail.hpp b/include/chaiscript/dispatchkit/proxy_functions_detail.hpp
index f8416a0..96f8896 100644
--- a/include/chaiscript/dispatchkit/proxy_functions_detail.hpp
+++ b/include/chaiscript/dispatchkit/proxy_functions_detail.hpp
@@ -77,7 +77,7 @@ namespace chaiscript
              const std::vector<Boxed_Value> &params, const Type_Conversions_State &t_conversions)
         {
           try {
-            int i = 0;
+            std::vector<Boxed_Value>::size_type i = 0;
             (void)params; (void)t_conversions;
             // this is ok because the order of evaluation of initializer lists is well defined
             (void)std::initializer_list<int>{(boxed_cast<Params>(params[i++], &t_conversions), 0)...};