diff --git a/python/sglang/srt/layers/moe/topk.py b/python/sglang/srt/layers/moe/topk.py
index bf8981c13..e3c7018bb 100644
--- a/python/sglang/srt/layers/moe/topk.py
+++ b/python/sglang/srt/layers/moe/topk.py
@@ -709,8 +709,10 @@ def biased_grouped_topk_cpu(
     routed_scaling_factor: Optional[float] = None,
     num_token_non_padded: Optional[torch.Tensor] = None,
     expert_location_dispatch_info: Optional[ExpertLocationDispatchInfo] = None,
+    apply_routed_scaling_factor_on_output: Optional[bool] = False,
 ):
     assert expert_location_dispatch_info is None
+    assert not apply_routed_scaling_factor_on_output, "Not implemented"
     return torch.ops.sgl_kernel.biased_grouped_topk_cpu(
         hidden_states,
         gating_output,