diff --git a/include/toml11/traits.hpp b/include/toml11/traits.hpp
index 49b7ff3..6121f02 100644
--- a/include/toml11/traits.hpp
+++ b/include/toml11/traits.hpp
@@ -165,6 +165,12 @@ struct is_std_tuple_impl<std::tuple<Ts...>> : std::true_type{};
 template<typename T>
 using is_std_tuple = is_std_tuple_impl<cxx::remove_cvref_t<T>>;
 
+template<typename T> struct is_unordered_set_impl : std::false_type {};
+template<typename T, typename Hash, typename KeyEqual, typename Alloc>
+struct is_unordered_set_impl<std::unordered_set<T, Hash, KeyEqual, Alloc>> : std::true_type {};
+template<typename T>
+using is_unordered_set = is_unordered_set_impl<cxx::remove_cvref_t<T>>;
+
 #if defined(TOML11_HAS_OPTIONAL)
 template<typename T> struct is_std_optional_impl : std::false_type{};
 template<typename T>