--- interfaces.inc.orig	2014-05-01 22:02:44.000000000 +0200
+++ interfaces.inc	2014-06-14 01:25:39.216359000 +0200
@@ -4177,18 +4177,22 @@
 	$ifdescrs = get_configured_interface_list();
 	foreach ($ifdescrs as $ifdescr => $ifname) {
 		/* check IPv4 */
 		if(is_ipaddrv4($carp_ip)) {
 			$interfaceip = get_interface_ip($ifname);
+			if(!is_ipaddrv4($interfaceip))
+				continue;
 			$subnet_bits = get_interface_subnet($ifname);
 			$subnet_ip = gen_subnet("{$interfaceip}", "{$subnet_bits}");
 			if(ip_in_subnet($carp_ip, "{$subnet_ip}/{$subnet_bits}"))
 				return $ifname;
 		}
 		/* Check IPv6 */
 		if(is_ipaddrv6($carp_ipv6)) {
 			$interfaceipv6 = get_interface_ipv6($ifname);
+			if(!is_ipaddrv6($interfaceipv6))
+				continue;
 			$prefixlen = get_interface_subnetv6($ifname);
 			if(ip_in_subnet($carp_ipv6, "{$interfaceipv6}/{$prefixlen}"))
 				return $ifname;
 		}
 	}