--- radvd-1.1.orig/includes.h	2007-10-25 21:29:40.000000000 +0200
+++ radvd-1.1/includes.h	2008-06-14 12:30:25.000000000 +0200
@@ -18,6 +18,8 @@
 
 #include <config.h>
 
+#define _GNU_SOURCE /* needed for struct in6_pktinfo */
+
 #include <string.h>
 #include <stdio.h>
 #include <stdarg.h>