diff --git a/python/sglang/srt/managers/scheduler.py b/python/sglang/srt/managers/scheduler.py
index de3c753ef..75a3af8ee 100644
--- a/python/sglang/srt/managers/scheduler.py
+++ b/python/sglang/srt/managers/scheduler.py
@@ -1388,8 +1388,8 @@ def run_scheduler_process(
     pipe_writer,
 ):
     # [For Router] if env var "DP_RANK" exist, set dp_rank to the value of the env var
-    if dp_rank is None:
-        dp_rank = int(os.getenv("DP_RANK", -1))
+    if dp_rank is None and "DP_RANK" in os.environ:
+        dp_rank = int(os["DP_RANK"])
 
     if dp_rank is None:
         configure_logger(server_args, prefix=f" TP{tp_rank}")