diff --git a/expo/data/custom_task.py b/expo/data/custom_task.py
index 032fcb8ac..c2bf5c710 100644
--- a/expo/data/custom_task.py
+++ b/expo/data/custom_task.py
@@ -21,7 +21,7 @@ COMPETITION INSTRUCTIONS
 {task_description}
 
 ## More Instructions
-- You should split the training data into train and dev set.
+- You should split the training data into train and dev set with a seed of 42.
 - You should use the dev set to improve your model. Print the final dev set score after training.
 - output_dir: {output_dir}
 - Besides `submission.csv`, you should also save your `test_predictions.csv` and `dev_predictions.csv` in the output directory.