diff --git a/main.py b/main.py
index 25bdcb6..c78e1b2 100644
--- a/main.py
+++ b/main.py
@@ -12,6 +12,7 @@ from fastapi.responses import PlainTextResponse
 from fastapi.middleware.gzip import GZipMiddleware
 from tjnetwork import *
 import asyncio
+import threading
 
 JUNCTION = 0
 RESERVOIR = 1
@@ -145,7 +146,7 @@ async def fastapi_dump_inp(network: str, inp: str) -> bool:
     dump_inp(network, inp)
     return True
 
-lock = asyncio.Lock()
+lock = threading.Lock()
 
 # 必须用这个PlainTextResponse，不然每个key都有引号
 @app.get("/runproject/", response_class = PlainTextResponse)
@@ -154,7 +155,7 @@ async def fastapi_run_project(network: str) -> str:
         raise HTTPException(status_code=400, detail="is in simulation")
     else:
         try:
-            async with lock:
+            with lock:
                 result = run_project(network)
                 return result
         except asyncio.CancelledError: