--- a/src/Network/Session.hh	Fri Sep 11 15:34:48 2009 +0300
+++ b/src/Network/Session.hh	Sun Jun 02 16:15:23 2013 +0300
@@ -9,6 +9,7 @@
 
 #include <map>
 #include <stdint.h>
+#include <stddef.h>
 
 // forward-declare
 class NetworkSession;