diff --git a/main.py b/main.py
index c7fe776..c8cb70b 100644
--- a/main.py
+++ b/main.py
@@ -150,6 +150,7 @@ async def fastapi_dump_inp(network: str, inp: str) -> bool:
 # 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: