diff --git a/include/boost/container_hash/hash.hpp b/include/boost/container_hash/hash.hpp
index 092d256..c34a78c 100644
--- a/include/boost/container_hash/hash.hpp
+++ b/include/boost/container_hash/hash.hpp
@@ -14,6 +14,7 @@
 #include <boost/container_hash/is_range.hpp>
 #include <boost/container_hash/is_contiguous_range.hpp>
 #include <boost/container_hash/is_unordered_range.hpp>
+#include <boost/container_hash/is_described_class.hpp>
 #include <boost/container_hash/detail/hash_tuple.hpp>
 #include <boost/container_hash/detail/hash_mix.hpp>
 #include <boost/container_hash/detail/hash_range.hpp>
diff --git a/include/boost/container_hash/hash_fwd.hpp b/include/boost/container_hash/hash_fwd.hpp
index f3a30e5..489fdd2 100644
--- a/include/boost/container_hash/hash_fwd.hpp
+++ b/include/boost/container_hash/hash_fwd.hpp
@@ -1,5 +1,5 @@
 // Copyright 2005-2009 Daniel James.
-// Copyright 2021 Peter Dimov.
+// Copyright 2021, 2022 Peter Dimov.
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
@@ -17,6 +17,7 @@ namespace container_hash
 template<class T> struct is_range;
 template<class T> struct is_contiguous_range;
 template<class T> struct is_unordered_range;
+template<class T> struct is_described_class;
 
 } // namespace container_hash