diff --git a/python/sglang/srt/disaggregation/decode.py b/python/sglang/srt/disaggregation/decode.py
index 148392922..7d8630c5c 100644
--- a/python/sglang/srt/disaggregation/decode.py
+++ b/python/sglang/srt/disaggregation/decode.py
@@ -374,6 +374,9 @@ class DecodePreallocQueue:
         if prefill_info is None:
             return None
 
+        if prefill_info.dp_size == 1:
+            return 0
+
         if prefill_info.follow_bootstrap_room:
             return req.bootstrap_room % prefill_info.dp_size