diff --git a/vllm_ascend/utils.py b/vllm_ascend/utils.py
index aec8decf..b7d1bae1 100644
--- a/vllm_ascend/utils.py
+++ b/vllm_ascend/utils.py
@@ -485,7 +485,10 @@ def update_aclgraph_sizes(vllm_config: VllmConfig) -> None:
     resources_per_graph = num_hidden_layers + 1
     # For suffix decoding, use the suffix path when no draft_model_config is provided.
     if (spec := vllm_config.speculative_config) and (draft := spec.draft_model_config):
-        resources_per_graph += draft.hf_config.num_hidden_layers + 1
+        # Use get_total_num_hidden_layers() to correctly handle MTP models,
+        # which store layer count in num_nextn_predict_layers or
+        # mtp_num_hidden_layers (for Qwen3.5) instead of num_hidden_layers.
+        resources_per_graph += draft.get_total_num_hidden_layers() + 1
 
     # TODO: Find out whether we need to take into account the pp_size
     num_comm_groups = sum(