diff --git a/autogen/logger/file_logger.py b/autogen/logger/file_logger.py
index 37bbbd25a523..07c9c3b76a76 100644
--- a/autogen/logger/file_logger.py
+++ b/autogen/logger/file_logger.py
@@ -90,7 +90,7 @@ def log_chat_completion(
         thread_id = threading.get_ident()
         source_name = None
         if isinstance(source, str):
-            source_name = source
+            source_name = getattr(source, "name", "unknown")
         else:
             source_name = source.name
         try: