diff -ur zabbix-2.4.3.orig/src/libs/zbxserver/expression.c zabbix-2.4.3/src/libs/zbxserver/expression.c
--- zabbix-2.4.3.orig/src/libs/zbxserver/expression.c	2014-12-16 09:37:44.000000000 +0300
+++ zabbix-2.4.3/src/libs/zbxserver/expression.c	2015-02-11 17:07:29.000000000 +0300
@@ -2895,6 +2895,10 @@
 				{
 					ret = get_autoreg_value_by_event(c_event, &replace_to, "listen_ip");
 				}
+				else if (0 == strcmp(m, MVAR_HOST_DNS))
+				{
+					ret = get_autoreg_value_by_event(c_event, &replace_to, "listen_dns");
+				}
 				else if (0 == strcmp(m, MVAR_HOST_PORT))
 				{
 					ret = get_autoreg_value_by_event(c_event, &replace_to, "listen_port");