diff --git a/server/internal/store/codes_lib_migrate_test.go b/server/internal/store/codes_lib_migrate_test.go
index 529c2ae..9dbd61b 100644
--- a/server/internal/store/codes_lib_migrate_test.go
+++ b/server/internal/store/codes_lib_migrate_test.go
@@ -104,29 +104,12 @@ func TestCodesLibMigrateRoundTrip(t *testing.T) {
 	// the reviewer's repro hit: the lib's `codes` table collides with the
 	// name 000022's down script renames legacy_codes back to.
 	m := newSQLiteStepper(t, db)
-	// 000027 (pay_promo_paid_unique), 000026 (notices), 000025
-	// (user_device_limit_override), 000024 (invite_rewards) and 000023
-	// (pay_purchases/source-enum) now sit on top of 000022
-	// (codes_lib_legacy_rename) and are unrelated to this collision — step
-	// them back down first so we land exactly on the 000022 boundary the
-	// test targets.
-	if err := m.Steps(-1); err != nil {
-		t.Fatalf("step 000027 down: %v", err)
-	}
-	if err := m.Steps(-1); err != nil {
-		t.Fatalf("step 000026 down: %v", err)
-	}
-	if err := m.Steps(-1); err != nil {
-		t.Fatalf("step 000025 down: %v", err)
-	}
-	if err := m.Steps(-1); err != nil {
-		t.Fatalf("step 000024 down: %v", err)
-	}
-	if err := m.Steps(-1); err != nil {
-		t.Fatalf("step 000023 down: %v", err)
-	}
-	if err := m.Steps(-1); err != nil {
-		t.Fatalf("step 000022 down: %v (this is the reviewer-reported collision — "+
+	// 所有排在 000022 之上的迁移(000023..最新,如 pay_purchases / invite_rewards /
+	// notices / routing_profiles …)都与本冲突无关 —— 一次性降到版本 21,恰好落在
+	// 000022(codes_lib_legacy_rename)down 之后的边界。用版本号显式定位而非硬编码
+	// Steps(-1) 计数,避免栈顶新增迁移(如 000028)后步数漂移、跳过 000022 down。
+	if err := m.Migrate(21); err != nil {
+		t.Fatalf("migrate down to v21 (past 000022 down): %v (this is the reviewer-reported collision — "+
 			"000022 down must DROP the codes-lib tables before renaming legacy_* back)", err)
 	}