diff --git a/src/transformers/trainer.py b/src/transformers/trainer.py
index b1adeb66eaac..bc504e785e71 100755
--- a/src/transformers/trainer.py
+++ b/src/transformers/trainer.py
@@ -16,6 +16,7 @@
 The Trainer class, to easily train a 🤗 Transformers from scratch or finetune it on a new task.
 """
 
+import contextlib
 import functools
 import glob
 import inspect