diff --git a/include/beast/core/detail/type_traits.hpp b/include/beast/core/detail/type_traits.hpp
index 3f6108cc..24928abd 100644
--- a/include/beast/core/detail/type_traits.hpp
+++ b/include/beast/core/detail/type_traits.hpp
@@ -8,6 +8,7 @@
 #ifndef BEAST_DETAIL_TYPE_TRAITS_HPP
 #define BEAST_DETAIL_TYPE_TRAITS_HPP
 
+#include <tuple>
 #include <type_traits>
 
 namespace beast {