diff --git a/django/contrib/sessions/backends/file.py b/django/contrib/sessions/backends/file.py
index 1540139710..36a03b6353 100644
--- a/django/contrib/sessions/backends/file.py
+++ b/django/contrib/sessions/backends/file.py
@@ -1,3 +1,4 @@
+import errno
 import os
 import tempfile