diff --git a/epmet-user/epmet-user-server/src/main/resources/db/migration/V0.0.28__nat_add_uniquekey.sql b/epmet-user/epmet-user-server/src/main/resources/db/migration/V0.0.28__nat_add_uniquekey.sql
index 5cf24b3bec..76b6b17b34 100644
--- a/epmet-user/epmet-user-server/src/main/resources/db/migration/V0.0.28__nat_add_uniquekey.sql
+++ b/epmet-user/epmet-user-server/src/main/resources/db/migration/V0.0.28__nat_add_uniquekey.sql
@@ -1 +1 @@
-alter table ic_nat add index unq_nat(ID_CARD, NAT_TIME)
\ No newline at end of file
+alter table ic_nat add unique index unq_nat(ID_CARD, NAT_TIME)
\ No newline at end of file