diff --git a/targets/hasura/migrations/1595231600880_alerts_uniq/down.sql b/targets/hasura/migrations/1595231600880_alerts_uniq/down.sql
index 906d71e50..acbded61f 100644
--- a/targets/hasura/migrations/1595231600880_alerts_uniq/down.sql
+++ b/targets/hasura/migrations/1595231600880_alerts_uniq/down.sql
@@ -1,2 +1,2 @@
 ALTER TABLE "public"."alerts"
-  DROP CONSTRAINT "alerts_ref_info_key";
+  DROP IF EXISTS CONSTRAINT "alerts_ref_info_key";
diff --git a/targets/hasura/migrations/1595231600880_alerts_uniq/up.sql b/targets/hasura/migrations/1595231600880_alerts_uniq/up.sql
index fcbb5923a..0041da1be 100644
--- a/targets/hasura/migrations/1595231600880_alerts_uniq/up.sql
+++ b/targets/hasura/migrations/1595231600880_alerts_uniq/up.sql
@@ -1,4 +1,8 @@
+ALTER TABLE "public"."alerts"
+  DROP CONSTRAINT IF EXISTS "alerts_ref_info_key";
 
-alter table "public"."alerts" add constraint "alerts_ref_info_key" unique ("ref", "info");
+ALTER TABLE "public"."alerts"
+  ADD CONSTRAINT "alerts_ref_info_key" UNIQUE ("ref", "info");
 
-DELETE FROM alerts where (info -> 'type') is null;
+DELETE FROM alerts
+WHERE (info -> 'type') IS NULL;