diff --git a/train_util.py b/train_util.py
index e91a6bc..f2e69a5 100644
--- a/train_util.py
+++ b/train_util.py
@@ -4,6 +4,7 @@ import logging
 import sys
 import time
 import csv
+import json
 from datetime import datetime
 from pathlib import Path
 from typing import Any, Dict, Tuple