diff --git a/apps/setting/models_provider/impl/base_chat_open_ai.py b/apps/setting/models_provider/impl/base_chat_open_ai.py
index 7b5f3355c..efdc22a8f 100644
--- a/apps/setting/models_provider/impl/base_chat_open_ai.py
+++ b/apps/setting/models_provider/impl/base_chat_open_ai.py
@@ -133,7 +133,7 @@ class BaseChatOpenAI(ChatOpenAI):
         )
 
         usage_metadata: Optional[UsageMetadata] = (
-            _create_usage_metadata(token_usage) if token_usage.get("prompt_tokens") else None
+            _create_usage_metadata(token_usage) if token_usage.get("prompt_tokens") else {}
         )
         if len(choices) == 0:
             # logprobs is implicitly None