diff --git a/backend/apps/openai/main.py b/backend/apps/openai/main.py
index a39b2787e..948ee7c46 100644
--- a/backend/apps/openai/main.py
+++ b/backend/apps/openai/main.py
@@ -358,7 +358,7 @@ async def generate_chat_completion(
     payload = {**form_data}
 
     if "metadata" in payload:
-        payload.pop("metadata")
+        del payload["metadata"]
 
     model_id = form_data.get("model")
     model_info = Models.get_model_by_id(model_id)