diff --git a/src/main/kotlin/com/android/trisolarisserver/config/IssuedCardSchemaFix.kt b/src/main/kotlin/com/android/trisolarisserver/config/IssuedCardSchemaFix.kt
index 43d88b1..34979f2 100644
--- a/src/main/kotlin/com/android/trisolarisserver/config/IssuedCardSchemaFix.kt
+++ b/src/main/kotlin/com/android/trisolarisserver/config/IssuedCardSchemaFix.kt
@@ -34,5 +34,39 @@ class IssuedCardSchemaFix(
             logger.info("Dropping NOT NULL on issued_card.room_stay_id")
             jdbcTemplate.execute("alter table issued_card alter column room_stay_id drop not null")
         }
+
+        val uniqueIndexExists = jdbcTemplate.queryForObject(
+            """
+            select count(*)
+            from pg_indexes
+            where schemaname = 'public'
+              and tablename = 'issued_card'
+              and indexname = 'idx_issued_card_property_card_id_unique'
+            """.trimIndent(),
+            Int::class.java
+        ) ?: 0
+
+        if (uniqueIndexExists == 0) {
+            logger.info("Removing duplicate issued_card rows by property_id + card_id")
+            jdbcTemplate.execute(
+                """
+                with ranked as (
+                    select id,
+                           row_number() over (
+                               partition by property_id, lower(card_id)
+                               order by issued_at desc, id desc
+                           ) as rn
+                    from issued_card
+                    where card_id is not null
+                )
+                delete from issued_card
+                where id in (select id from ranked where rn > 1)
+                """.trimIndent()
+            )
+            logger.info("Creating unique index on issued_card(property_id, lower(card_id))")
+            jdbcTemplate.execute(
+                "create unique index if not exists idx_issued_card_property_card_id_unique on issued_card (property_id, lower(card_id))"
+            )
+        }
     }
 }