diff --git a/python/sglang/srt/managers/schedule_batch.py b/python/sglang/srt/managers/schedule_batch.py
index f4ffed10b1d..76e242a3cfd 100644
--- a/python/sglang/srt/managers/schedule_batch.py
+++ b/python/sglang/srt/managers/schedule_batch.py
@@ -368,7 +368,7 @@ def adjust_max_prefix_ids(self):
         # request has at least one token. Later, we can relax this requirement and use `input_len`.
         max_prefix_len = input_len - 1
 
-        if self.sampling_params.max_new_tokens > 0:
+        if (self.sampling_params.max_new_tokens or 0) > 0:
             # Need at least one token to compute logits
             max_prefix_len = min(max_prefix_len, input_len - 1)