diff --git a/src/services/maintenance.ts b/src/services/maintenance.ts
index 8d74472..90e7c34 100644
--- a/src/services/maintenance.ts
+++ b/src/services/maintenance.ts
@@ -67,8 +67,8 @@ export class MaintenanceService {
   static async cleanupInactiveMembersOnce(instance?: Database, retentionDays: number = this.retentionDays): Promise<number> {
     if (retentionDays <= 0) return 0;
     const threshold = toIsoSqlUTC(new Date(Date.now() - retentionDays * 24 * 60 * 60 * 1000));
-    instance = (instance ?? (this as any).dbInstance ?? getDb()) as Database;
-    const res = instance.prepare(`
+    const dbi = ((instance ?? (this as any).dbInstance ?? getDb()) as Database);
+    const res = dbi.prepare(`
       DELETE FROM group_members
       WHERE is_active = 0
         AND last_seen_at < ?
@@ -84,18 +84,18 @@ export class MaintenanceService {
    */
   static async reconcileAliasUsersOnce(instance?: Database): Promise<number> {
     try {
-      instance = (instance ?? (this as any).dbInstance ?? getDb()) as Database;
-      const rows = instance.prepare(`SELECT alias, user_id FROM user_aliases WHERE alias != user_id`).all() as any[];
+      const dbi = ((instance ?? (this as any).dbInstance ?? getDb()) as Database);
+      const rows = dbi.prepare(`SELECT alias, user_id FROM user_aliases WHERE alias != user_id`).all() as any[];
       let merged = 0;
 
       for (const r of rows) {
         const alias = String(r.alias);
         const real = String(r.user_id);
 
-        instance.transaction(() => {
+        dbi.transaction(() => {
           // Asegurar existencia del usuario real
           try {
-            instance.prepare(`INSERT OR IGNORE INTO users (id) VALUES (?)`)
+            dbi.prepare(`INSERT OR IGNORE INTO users (id) VALUES (?)`)
               .run(real);
           } catch {}
 
@@ -110,7 +110,7 @@ export class MaintenanceService {
 
           for (const sql of updates) {
             try {
-              instance.prepare(sql).run(real, alias);
+              dbi.prepare(sql).run(real, alias);
             } catch {
               // Ignorar si la tabla no existe en este despliegue
             }
@@ -118,7 +118,7 @@ export class MaintenanceService {
 
           // Intentar eliminar el usuario alias si ya no tiene referencias
           try {
-            instance.prepare(`DELETE FROM users WHERE id = ?`).run(alias);
+            dbi.prepare(`DELETE FROM users WHERE id = ?`).run(alias);
           } catch {}
         })();