diff --git a/include/boost/container_hash/hash.hpp b/include/boost/container_hash/hash.hpp
index 06fa8a3..5ce09d4 100644
--- a/include/boost/container_hash/hash.hpp
+++ b/include/boost/container_hash/hash.hpp
@@ -308,7 +308,7 @@ namespace boost
              return seed;
         }
 
-        template<int Bits> struct hash_combine_impl
+        template<std::size_t Bits> struct hash_combine_impl
         {
             template <typename SizeT>
             inline static SizeT fn(SizeT seed, SizeT value)