diff -uNr dhcp-4.0.0.ORIG/common/socket.c dhcp-4.0.0/common/socket.c
--- dhcp-4.0.0.ORIG/common/socket.c	2008-09-02 10:25:21.000000000 +0100
+++ dhcp-4.0.0/common/socket.c	2008-09-02 10:27:29.000000000 +0100
@@ -46,6 +46,10 @@
 #include <sys/uio.h>
 #include <sys/uio.h>
 
+#ifdef HAVE_LINUX_IPV6_H
+#include <linux/ipv6.h>
+#endif
+
 #ifdef USE_SOCKET_FALLBACK
 # if !defined (USE_SOCKET_SEND)
 #  define if_register_send if_register_fallback
diff -uNr dhcp-4.0.0.ORIG/configure.ac dhcp-4.0.0/configure.ac
--- dhcp-4.0.0.ORIG/configure.ac	2008-09-02 10:25:21.000000000 +0100
+++ dhcp-4.0.0/configure.ac	2008-09-02 10:26:29.000000000 +0100
@@ -37,6 +37,7 @@
 if test "$enable_dhcpv6" != "no"; then
 	AC_DEFINE([DHCPv6], [1], 
 		  [Define to 1 to include DHCPv6 support.])
+	AC_CHECK_HEADERS(linux/ipv6.h)
 fi
 
 ###