diff --git a/procfs/procfs.py b/procfs/procfs.py
index c70fe2a..c6f6589 100755
--- a/procfs/procfs.py
+++ b/procfs/procfs.py
@@ -21,6 +21,7 @@
 from __future__ import absolute_import
 from __future__ import print_function
 import os, time
+from functools import reduce
 from .utilist import bitmasklist
 from six.moves import range