diff --git a/examples/chatgpt/src/chatgpt_bridge/utils.py b/examples/chatgpt/src/chatgpt_bridge/utils.py
index 8586e94..0a0d9d8 100644
--- a/examples/chatgpt/src/chatgpt_bridge/utils.py
+++ b/examples/chatgpt/src/chatgpt_bridge/utils.py
@@ -14,9 +14,9 @@ def json_error(message: str, status: int = 400) -> Response:
 
 class OpenaiFileIdRef(BaseModel):
     # https://platform.openai.com/docs/actions/sending-files
-    id: str
-    name: str
-    mime_type: str
+    id: str | None = None
+    name: str | None = None
+    mime_type: str | None = None
     download_link: str