Index: boost/date_time/filetime_functions.hpp
===================================================================
--- boost/date_time/filetime_functions.hpp	(revision 50857)
+++ boost/date_time/filetime_functions.hpp	(working copy)
@@ -25,6 +25,7 @@
 
 #include <boost/cstdint.hpp>
 #include <boost/date_time/time.hpp>
+#include <boost/date_time/date_defs.hpp>
 
 namespace boost {