diff --git a/internal/migrator/migrations/postgres/000010_rename_attempts_pkey.down.sql b/internal/migrator/migrations/postgres/000010_rename_attempts_pkey.down.sql
new file mode 100644
index 000000000..8662cc4f4
--- /dev/null
+++ b/internal/migrator/migrations/postgres/000010_rename_attempts_pkey.down.sql
@@ -0,0 +1,6 @@
+BEGIN;
+
+ALTER INDEX IF EXISTS attempts_pkey RENAME TO deliveries_pkey;
+ALTER INDEX IF EXISTS attempts_default_pkey RENAME TO deliveries_default_pkey;
+
+COMMIT;
diff --git a/internal/migrator/migrations/postgres/000010_rename_attempts_pkey.up.sql b/internal/migrator/migrations/postgres/000010_rename_attempts_pkey.up.sql
new file mode 100644
index 000000000..20c53e796
--- /dev/null
+++ b/internal/migrator/migrations/postgres/000010_rename_attempts_pkey.up.sql
@@ -0,0 +1,18 @@
+BEGIN;
+
+-- =============================================================================
+-- Migration: Rename the stale deliveries_* primary key indexes to attempts_*
+--
+-- 000005 renamed the deliveries tables to attempts, but Postgres does not
+-- rename dependent indexes and constraints on a table rename, so the primary
+-- key of attempts (and of its default partition) still carries the old name.
+--
+-- Indexes renamed:
+--   deliveries_pkey         -> attempts_pkey
+--   deliveries_default_pkey -> attempts_default_pkey
+-- =============================================================================
+
+ALTER INDEX IF EXISTS deliveries_pkey RENAME TO attempts_pkey;
+ALTER INDEX IF EXISTS deliveries_default_pkey RENAME TO attempts_default_pkey;
+
+COMMIT;