diff --git a/vllm_kunlun/v1/sample/ops/topk_topp_sampler.py b/vllm_kunlun/v1/sample/ops/topk_topp_sampler.py
index db5fa2f..08a33f9 100644
--- a/vllm_kunlun/v1/sample/ops/topk_topp_sampler.py
+++ b/vllm_kunlun/v1/sample/ops/topk_topp_sampler.py
@@ -42,7 +42,7 @@ class TopKTopPSampler(nn.Module):
         """
         logits = apply_top_k_top_p(logits, k, p)
         probs = logits.softmax(dim=-1, dtype=torch.float32)
-        return random_sample(probs, generators)
+        return random_sample(probs, generators), None
 
     def forward_kunlun(
         self,
@@ -199,4 +199,4 @@ def flashinfer_sample(
         next_token_ids = xtorch_ops.top_k_top_p_sampling_from_probs(
             probs, top_k=k, top_p=p, deterministic=True)
 
-    return next_token_ids.view(-1)
\ No newline at end of file
+    return next_token_ids.view(-1)