umax_pp.c:330: warning: implicit declaration of function 'putenv'

--- tools/umax_pp.c.orig	Tue Aug 28 09:29:19 2012
+++ tools/umax_pp.c	Tue Aug 28 09:29:29 2012
@@ -7,6 +7,7 @@
 
 /* For putenv */
 #define _XOPEN_SOURCE
+#define _XOPEN_SOURCE 700
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>