diff --git a/libs/util/include/psemek/util/hash.hpp b/libs/util/include/psemek/util/hash.hpp
index 701d93a4..2f8a77cd 100644
--- a/libs/util/include/psemek/util/hash.hpp
+++ b/libs/util/include/psemek/util/hash.hpp
@@ -6,9 +6,9 @@
 namespace psemek::util
 {
 
-	inline void hash_combine(std::size_t & seed, std::size_t value)
+	constexpr void hash_combine(std::size_t & seed, std::size_t value)
 	{
-		static const std::size_t k = 0x9ddfea08eb382d69ULL;
+		constexpr std::size_t k = 0x9ddfea08eb382d69ULL;
 		std::size_t a = (value ^ seed) * k;
 		a ^= (a >> 47);
 		std::size_t b = (seed ^ a) * k;
@@ -17,7 +17,7 @@ namespace psemek::util
 	}
 
 	template <typename Iterator, typename Hash = std::hash<std::decay_t<decltype(*std::declval<Iterator>())>>>
-	void hash_sequence(std::size_t & seed, Iterator begin, Iterator end, Hash hash = Hash{})
+	constexpr void hash_sequence(std::size_t & seed, Iterator begin, Iterator end, Hash hash = Hash{})
 	{
 		for (; begin != end; ++begin)
 		{