diff --git a/main.py b/main.py
index c8cb70b..25bdcb6 100644
--- a/main.py
+++ b/main.py
@@ -34,8 +34,6 @@ if not os.path.exists(tmpDir):
 
 app = FastAPI()
 
-lock = asyncio.Lock()
-
 app.add_middleware(GZipMiddleware, minimum_size=1000)
 
 ############################################################
@@ -147,10 +145,11 @@ async def fastapi_dump_inp(network: str, inp: str) -> bool:
     dump_inp(network, inp)
     return True
 
+lock = asyncio.Lock()
+
 # 必须用这个PlainTextResponse，不然每个key都有引号
 @app.get("/runproject/", response_class = PlainTextResponse)
 async def fastapi_run_project(network: str) -> str:
-    global lock
     if lock.locked():
         raise HTTPException(status_code=400, detail="is in simulation")
     else: