diff --git a/include/boost/type_traits.hpp b/include/boost/type_traits.hpp
index 04dcc68..d84f05b 100644
--- a/include/boost/type_traits.hpp
+++ b/include/boost/type_traits.hpp
@@ -20,6 +20,7 @@
 #include <boost/type_traits/object_traits.hpp>
 #include <boost/type_traits/transform_traits.hpp>
 #include <boost/type_traits/same_traits.hpp>
+#include <boost/type_traits/function_traits.hpp>
 
 /**************************************************************************/