diff --git a/mammoth/models/model_saver.py b/mammoth/models/model_saver.py
index b69ed409..f39562af 100644
--- a/mammoth/models/model_saver.py
+++ b/mammoth/models/model_saver.py
@@ -1,6 +1,6 @@
 import os
 from glob import glob
-from collections import deque, defaultdict
+from collections import deque
 from mammoth.utils.logging import logger
 
 import torch