diff --git a/vllm/v1/spec_decode/llm_base_proposer.py b/vllm/v1/spec_decode/llm_base_proposer.py
index 09e15c7b2..9a50c4c8d 100644
--- a/vllm/v1/spec_decode/llm_base_proposer.py
+++ b/vllm/v1/spec_decode/llm_base_proposer.py
@@ -1332,10 +1332,29 @@ class SpecDecodeBaseProposer:
         Subclasses may override to apply additional config changes.
         """
         spec_cfg = self.speculative_config
+        draft_parallel_config = spec_cfg.draft_parallel_config
+        # create_draft_parallel_config() does not copy
+        # decode_context_parallel_size from the target, so the draft
+        # attention silently runs with dcp=1 (no q-allgather, no LSE merge)
+        # while its KV/metadata use DCP-local sharded semantics. The V2
+        # runner path (gpu/spec_decode/eagle/utils.py) restores the target
+        # DCP for native MTP drafts; mirror that here for the V1 path.
+        import os as _os
+
+        default_shard_draft = "1" if spec_cfg.method == "mtp" else "0"
+        if _os.environ.get(
+            "VLLM_DCP_SHARD_DRAFT", default_shard_draft
+        ).lower() in ("1", "true", "yes"):
+            draft_parallel_config = replace(
+                draft_parallel_config,
+                decode_context_parallel_size=(
+                    self.vllm_config.parallel_config.decode_context_parallel_size
+                ),
+            )
         config = replace(
             self.vllm_config,
             parallel_config=replace(
-                spec_cfg.draft_parallel_config,
+                draft_parallel_config,
                 rank=self.vllm_config.parallel_config.rank,
             ),
             model_config=spec_cfg.draft_model_config,