diff --git a/examples/api_request_parallel_processor.py b/examples/api_request_parallel_processor.py
index cc6cd47d..861fdc91 100644
--- a/examples/api_request_parallel_processor.py
+++ b/examples/api_request_parallel_processor.py
@@ -298,7 +298,7 @@ class APIRequest:
                 retry_queue.put_nowait(self)
             else:
                 logging.error(f"Request {self.request_json} failed after all attempts. Saving errors: {self.result}")
-                append_to_jsonl([self.request_json, self.result], save_filepath)
+                append_to_jsonl([self.request_json, [str(e) for e in self.result]], save_filepath)
                 status_tracker.num_tasks_in_progress -= 1
                 status_tracker.num_tasks_failed += 1
         else: