diff --git a/src/nat_porttrigger.c b/src/nat_porttrigger.c
index dd486f8f42ae353cf893c1bd50fe96c993129516..919ace6aad5657fb080ad2eb342c7245c6f3eb7e 100644
--- a/src/nat_porttrigger.c
+++ b/src/nat_porttrigger.c
@@ -463,7 +463,7 @@ static int set_NATPortTriggerRule_Protocol(char *refparam, struct dmctx *ctx, vo
 
 DMLEAF tNATPortTriggerParams[] = {
 /* PARAM, permission, type, getvalue, setvalue, bbfdm_type */
-{"Alias", &DMREAD, DMT_STRING, get_NATPortTrigger_Alias, NULL, BBFDM_BOTH},
+{"Alias", &DMREAD, DMT_STRING, get_NATPortTrigger_Alias, NULL, BBFDM_BOTH, DM_FLAG_UNIQUE},
 {"Enable", &DMWRITE, DMT_BOOL, get_NATPortTrigger_Enable, set_NATPortTrigger_Enable, BBFDM_BOTH},
 {"Status", &DMREAD, DMT_STRING, get_NATPortTrigger_Status, NULL, BBFDM_BOTH},
 {"Origin", &DMWRITE, DMT_STRING, get_NATPortTrigger_Origin, set_NATPortTrigger_Origin, BBFDM_BOTH},
@@ -481,7 +481,7 @@ DMLEAF tNATPortTriggerParams[] = {
 /* *** Device.NAT.PortTrigger.{i}.Rule.{i}. *** */
 DMLEAF tNATPortTriggerRuleParams[] = {
 /* PARAM, permission, type, getvalue, setvalue, bbfdm_type */
-{"Alias", &DMREAD, DMT_STRING, get_NATPortTriggerRule_Alias, NULL, BBFDM_BOTH},
+{"Alias", &DMREAD, DMT_STRING, get_NATPortTriggerRule_Alias, NULL, BBFDM_BOTH, DM_FLAG_UNIQUE},
 {"Port", &DMWRITE, DMT_UNINT, get_NATPortTriggerRule_Port, set_NATPortTriggerRule_Port, BBFDM_BOTH},
 {"PortEndRange", &DMWRITE, DMT_UNINT, get_NATPortTriggerRule_PortEndRange, set_NATPortTriggerRule_PortEndRange, BBFDM_BOTH},
 {"Protocol", &DMWRITE, DMT_STRING, get_NATPortTriggerRule_Protocol, set_NATPortTriggerRule_Protocol, BBFDM_BOTH},