diff --git a/include/jwt-cpp/jwt.h b/include/jwt-cpp/jwt.h
index 62c61dc5d..3ca44be23 100644
--- a/include/jwt-cpp/jwt.h
+++ b/include/jwt-cpp/jwt.h
@@ -895,22 +895,6 @@ namespace jwt {
 				is_as_integer_signature<T, value_type, integer_type>::value;
 		};
 
-		template<class...>
-		struct types {
-			using type = types;
-		};
-
-		template<class...> struct function_signature : std::false_type {};
-
-		template<class R, class Arg>
-		struct function_signature<R(Arg)> : std::true_type {
-			using args_t = typename std::decay<Arg>::type;
-			using return_t = typename std::decay<R>::type;
-			using signature_t = return_t(args_t);
-		};
-
-		template<class sig> struct function_signature : function_signature<decltype(sig)> {};
-
 		template <typename T>
 		using as_boolean_function = decltype(T::as_bool);
 
@@ -1038,8 +1022,6 @@ namespace jwt {
 		static_assert(details::supports_as_integer<traits, value_type, integer_type>::value, "traits must provide `integer_type as_int(const value_type&)`");
 		static_assert(details::supports_as_boolean<traits, value_type, boolean_type>::value, "traits must provide `boolean_type as_bool(const value_type&)`");
 
-		static_assert(std::is_same<details::function_signature<details::as_object_function<traits>>::args_t, value_type>::value, "");
-
 			value_type val;
 		public:
 			using set_t = std::set<string_type>;