diff -durN -x '*.orig' ntp-4.2.6p1.orig/ntpdate/ntpdate.c ntp-4.2.6p1/ntpdate/ntpdate.c
--- ntp-4.2.6p1.orig/ntpdate/ntpdate.c	2010-05-24 19:28:54.000000000 +0200
+++ ntp-4.2.6p1/ntpdate/ntpdate.c	2010-05-24 19:30:19.000000000 +0200
@@ -1729,11 +1729,13 @@
 		}
 #ifdef IPV6_V6ONLY
 		/* Restricts AF_INET6 socket to IPv6 communications (see RFC 2553bis-03) */
-		if (res->ai_family == AF_INET6)
-			if (setsockopt(fd[nbsock], IPPROTO_IPV6, IPV6_V6ONLY, (void*) &optval, sizeof(optval)) < 0) {
+		if (res->ai_family == AF_INET6) {
+			int i = setsockopt(fd[nbsock], IPPROTO_IPV6, IPV6_V6ONLY, (void*) &optval, sizeof(optval));
+			if ( i < 0 && errno != ENOPROTOOPT ) {
 				   msyslog(LOG_ERR, "setsockopt() IPV6_V6ONLY failed: %m");
 					exit(1);
 					/*NOTREACHED*/
+			}
 		}
 #endif