diff --git a/src/main.py b/src/main.py
index 7f05095..7fb2b31 100644
--- a/src/main.py
+++ b/src/main.py
@@ -1,9 +1,12 @@
 """v2.6 主入口 - FastAPI + Daemon ticker 共享 asyncio event loop"""
 
+from __future__ import annotations
+
 import asyncio
 import logging
 from contextlib import asynccontextmanager
 from pathlib import Path
+from typing import Optional
 
 import yaml
 from fastapi import FastAPI
@@ -33,7 +36,7 @@ config = load_config()
 # Daemon ticker（占位，F6 实现）
 # ---------------------------------------------------------------------------
 
-_ticker_task: asyncio.Task | None = None
+_ticker_task: Optional[asyncio.Task] = None
 
 
 async def _run_ticker():