diff --git a/src/rupload/app.py b/src/rupload/app.py
index 056206f..b66d726 100644
--- a/src/rupload/app.py
+++ b/src/rupload/app.py
@@ -281,7 +281,7 @@ async def handle_thumbnail(request: web.Request):
     except ValueError:
         return web.Response(status=404, text="File not found.")
     
-    thumbnail_path = pathlib.Path(safe_path).parent.joinpath(".thumbnail").joinpath(safe_path.name)
+    thumbnail_path = pathlib.Path(app.upload_path).joinpath(".thumbnail").joinpath(safe_path.name)
     if not thumbnail_path.parent.exists():
         thumbnail_path.parent.mkdir(exist_ok=True,parents=False)