diff --git a/include/boost/type_traits.hpp b/include/boost/type_traits.hpp
index 09ee938..4681f12 100644
--- a/include/boost/type_traits.hpp
+++ b/include/boost/type_traits.hpp
@@ -56,6 +56,7 @@
 #include "boost/type_traits/remove_reference.hpp"
 #include "boost/type_traits/remove_volatile.hpp"
 #include "boost/type_traits/type_with_alignment.hpp"
+#include "boost/type_traits/function_traits.hpp"
 
 #include "boost/type_traits/ice.hpp"