diff -up cups-1.3.5/scheduler/auth.c.peercred cups-1.3.5/scheduler/auth.c
--- cups-1.3.5/scheduler/auth.c.peercred	2008-02-05 16:52:20.000000000 +0000
+++ cups-1.3.5/scheduler/auth.c	2008-02-05 18:20:06.000000000 +0000
@@ -54,6 +54,7 @@
  * Include necessary headers...
  */
 
+#define _GNU_SOURCE
 #include "cupsd.h"
 #include <grp.h>
 #ifdef HAVE_SHADOW_H