diff --git a/mock/py/mock.py b/mock/py/mock.py
index 75960d1ce..4e058ee5a 100755
--- a/mock/py/mock.py
+++ b/mock/py/mock.py
@@ -55,6 +55,7 @@
 import signal
 import shutil
 import shlex
+import pipes
 import sys
 import time
 import copy