diff --git a/packages/prisma/migrations/20240924112248_booking_reference_null_credential_on_delete/migration.sql b/packages/prisma/migrations/20240924112248_booking_reference_null_credential_on_delete/migration.sql
index 4e01cc2b92..ab5b5799b5 100644
--- a/packages/prisma/migrations/20240924112248_booking_reference_null_credential_on_delete/migration.sql
+++ b/packages/prisma/migrations/20240924112248_booking_reference_null_credential_on_delete/migration.sql
@@ -2,10 +2,15 @@
 DROP INDEX "BookingReference_credentialId_idx";
 
 -- Remove disconnected Credentials from bookingReference to prevent foreign key constraint error
-UPDATE "BookingReference"
+UPDATE "BookingReference" br
 SET "credentialId" = NULL
-WHERE "credentialId" IS NOT NULL
-AND "credentialId" NOT IN (SELECT "id" FROM "Credential");
+WHERE br."credentialId" IS NOT NULL
+    AND br."credentialId" != 0
+    AND NOT EXISTS (
+        SELECT 1
+        FROM "Credential" c
+        WHERE c."id" = br."credentialId"
+    );
 
 -- AddForeignKey
 ALTER TABLE "BookingReference" ADD CONSTRAINT "BookingReference_credentialId_fkey" FOREIGN KEY ("credentialId") REFERENCES "Credential"("id") ON DELETE SET NULL ON UPDATE CASCADE;