diff --git a/litellm/utils.py b/litellm/utils.py
index 70e000a1a0..0e1573784b 100644
--- a/litellm/utils.py
+++ b/litellm/utils.py
@@ -5859,7 +5859,8 @@ def convert_to_model_response_object(
             if _response_headers is not None:
                 model_response_object._response_headers = _response_headers
 
-            special_keys = litellm.ModelResponse.model_fields.keys()
+            special_keys = list(litellm.ModelResponse.model_fields.keys())
+            special_keys.append("usage")
             for k, v in response_object.items():
                 if k not in special_keys:
                     setattr(model_response_object, k, v)