diff --git a/vllm/entrypoints/openai/responses/streaming_events.py b/vllm/entrypoints/openai/responses/streaming_events.py
index 9c463b3d5b..7447347fba 100644
--- a/vllm/entrypoints/openai/responses/streaming_events.py
+++ b/vllm/entrypoints/openai/responses/streaming_events.py
@@ -491,7 +491,7 @@ def emit_function_call_done_events(
         type="function_call",
         arguments=arguments,
         name=function_name,
-        item_id=state.current_item_id,
+        id=state.current_item_id,
         output_index=state.current_output_index,
         sequence_number=-1,
         call_id=state.current_call_id,