diff --git a/litellm/integrations/langfuse.py b/litellm/integrations/langfuse.py
index caf5437b242..140dced9d32 100644
--- a/litellm/integrations/langfuse.py
+++ b/litellm/integrations/langfuse.py
@@ -135,7 +135,9 @@ class LangFuseLogger:
                 response_obj, litellm.ModelResponse
             ):
                 input = prompt
-                output = response_obj["choices"][0]["message"].json()
+                output = response_obj["choices"][0]["message"]
+                if isinstance(output, litellm.Message):
+                    output = output.json()
             elif response_obj is not None and isinstance(
                 response_obj, litellm.TextCompletionResponse
             ):