diff --git a/deps/ox/src/ox/std/typetraits.hpp b/deps/ox/src/ox/std/typetraits.hpp
index 34b20c8ef..7e3f09566 100644
--- a/deps/ox/src/ox/std/typetraits.hpp
+++ b/deps/ox/src/ox/std/typetraits.hpp
@@ -51,6 +51,8 @@ template<> struct is_integral<uint32_t>: ox::true_type {};
 template<> struct is_integral<int64_t> : ox::true_type {};
 template<> struct is_integral<uint64_t>: ox::true_type {};
 
+template<typename T>
+constexpr bool is_signed = ox::integral_constant<bool, T(-1) < T(0)>::value;
 
 // enable_if ///////////////////////////////////////////////////////////////////