diff --git a/vllm/config/parallel.py b/vllm/config/parallel.py
index 7fb3bef34b77a..11504fb083558 100644
--- a/vllm/config/parallel.py
+++ b/vllm/config/parallel.py
@@ -465,6 +465,7 @@ class ParallelConfig:
             # Derived/runtime topology, networking, or launch details
             "data_parallel_rank",
             "data_parallel_rank_local",
+            "data_parallel_size_local",
             "data_parallel_backend",
             "data_parallel_external_lb",
             "data_parallel_hybrid_lb",