diff --git a/libs/util/include/psemek/util/hash.hpp b/libs/util/include/psemek/util/hash.hpp
index 2c5dbd64..349a7b0b 100644
--- a/libs/util/include/psemek/util/hash.hpp
+++ b/libs/util/include/psemek/util/hash.hpp
@@ -32,6 +32,19 @@ namespace psemek::util
 namespace std
 {
 
+	template <typename T, typename H>
+	struct hash<std::pair<T, H>>
+		: std::pair<std::hash<T>, std::hash<H>>
+	{
+		std::size_t operator()(std::pair<T, H> const & x) const
+		{
+			std::size_t seed = 0;
+			::psemek::util::hash_combine(seed, this->first(x.first));
+			::psemek::util::hash_combine(seed, this->second(x.second));
+			return seed;
+		}
+	};
+
 	template <typename ... Ts>
 	struct hash<std::tuple<Ts...>>
 		: std::tuple<std::hash<Ts>...>