diff --git a/vllm_kunlun/v1/sample/ops/topk_topp_sampler.py b/vllm_kunlun/v1/sample/ops/topk_topp_sampler.py
index e45c426..31fdf4d 100644
--- a/vllm_kunlun/v1/sample/ops/topk_topp_sampler.py
+++ b/vllm_kunlun/v1/sample/ops/topk_topp_sampler.py
@@ -2,7 +2,7 @@
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
 from typing import Optional
-
+import os
 import torch
 import torch.nn as nn
 from packaging import version