diff --git a/src/agents/models/openai_responses.py b/src/agents/models/openai_responses.py
index 55c78d0245..849b590571 100644
--- a/src/agents/models/openai_responses.py
+++ b/src/agents/models/openai_responses.py
@@ -733,7 +733,6 @@ def _build_response_create_kwargs(
         prompt: ResponsePromptParam | None = None,
     ) -> dict[str, Any]:
         list_input = ItemHelpers.input_to_new_input_list(input)
-        list_input = _to_dump_compatible(list_input)
         list_input = self._remove_openai_responses_api_incompatible_fields(list_input)
 
         if model_settings.parallel_tool_calls and tools: