diff --git a/include/sol/call.hpp b/include/sol/call.hpp
index 2e9ae2d9..2ff17f9b 100644
--- a/include/sol/call.hpp
+++ b/include/sol/call.hpp
@@ -524,8 +524,8 @@ namespace sol {
 					else {
 						using traits_type = lua_bind_traits<F>;
 						using return_type = typename traits_type::return_type;
-						constexpr bool is_const = std::is_const_v<std::remove_reference_t<return_type>>;
-						if constexpr (is_const) {
+						constexpr bool ret_is_const = std::is_const_v<std::remove_reference_t<return_type>>;
+						if constexpr (ret_is_const) {
 							(void)fx;
 							(void)detail::swallow{ 0, (static_cast<void>(args), 0)... };
 							return luaL_error(L, "sol: cannot write to a readonly (const) variable");