diff --git a/app/main.py b/app/main.py
index 0349f5bad..468ea72d7 100644
--- a/app/main.py
+++ b/app/main.py
@@ -150,8 +150,9 @@ def create_app() -> FastAPI:
 # Use Scalar instead of Swagger
 @app.get("/docs", include_in_schema=False)
 async def scalar_html():
+    openapi_url = os.path.join(ROOT_PATH, app.openapi_url.lstrip("/"))
     return get_scalar_api_reference(
-        openapi_url=ROOT_PATH + app.openapi_url,
+        openapi_url=openapi_url,
         title=app.title,
     )