diff --git a/applications/ColossalChat/coati/distributed/launch.py b/applications/ColossalChat/coati/distributed/launch.py
index ef81bcbdd..c9e8d2ab2 100644
--- a/applications/ColossalChat/coati/distributed/launch.py
+++ b/applications/ColossalChat/coati/distributed/launch.py
@@ -1,4 +1,5 @@
 import copy
+import os
 import uuid
 from typing import Any, Dict, Optional
 
diff --git a/applications/ColossalChat/coati/distributed/producer.py b/applications/ColossalChat/coati/distributed/producer.py
index 75879278c..78964afa1 100644
--- a/applications/ColossalChat/coati/distributed/producer.py
+++ b/applications/ColossalChat/coati/distributed/producer.py
@@ -149,7 +149,7 @@ class BaseProducer:
             else:
                 raise ValueError(f"Unknown evaluation function type {evaluation_function_type}")
         else:
-            raise ValueError("eval_dataset_config is not defined")
+            print("No eval dataset provided, skip eval")
         self.device = get_current_device()
 
         # init backend
diff --git a/applications/ColossalChat/rl_example.py b/applications/ColossalChat/rl_example.py
index bfa0ab7d0..5aec7f5a6 100644
--- a/applications/ColossalChat/rl_example.py
+++ b/applications/ColossalChat/rl_example.py
@@ -14,7 +14,7 @@ if __name__ == "__main__":
         "-ed",
         "--eval-dataset",
         type=str,
-        default='{"eval task name":"data_eval.jsonl"}',
+        default=None,
         help="Evaluation dataset for each task, please use json format to specify the dataset for each task. \
         For example: {'task1':'data_eval_task1.jsonl', 'task2':'data_eval_task2.jsonl'}, the jsonl file should be in the same format as the training dataset. \
         The key is the task name, and the value is the path to the jsonl file",
@@ -265,10 +265,14 @@ if __name__ == "__main__":
         project_name=args.project,
         save_interval=args.save_interval,
         save_dir=os.path.join(args.save_dir, args.project.replace(" ", "_")),
-        eval_dataset_config={
-            k: {"path": v, "max_length": args.max_prompt_tokens, "system_prompt": args.system_prompt}
-            for k, v in json.loads(args.eval_dataset).items()
-        },
+        eval_dataset_config=(
+            {
+                k: {"path": v, "max_length": args.max_prompt_tokens, "system_prompt": args.system_prompt}
+                for k, v in json.loads(args.eval_dataset).items()
+            }
+            if args.eval_dataset
+            else None
+        ),
         eval_interval=args.eval_interval,
         eval_save_dir=os.path.join(args.eval_save_dir, args.project.replace(" ", "_")),
         eval_generation_config=eval_generation_config,