--- contrib/uuid-ossp/uuid-ossp.c	2012-08-02 01:21:00.000000000 +0300
+++ contrib/uuid-ossp/uuid-ossp.c	2012-08-02 01:22:22.000000000 +0300
@@ -9,6 +9,8 @@
  *-------------------------------------------------------------------------
  */
 
+#define _XOPEN_SOURCE
+
 #include "postgres.h"
 #include "fmgr.h"
 #include "utils/builtins.h"