diff --git a/lower-constraints.txt b/lower-constraints.txt
index 8901234..5e5d923 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -36,7 +36,6 @@ keystoneauth1==3.4.0
 libvirt-python==3.5.0
 linecache2==1.0.0
 MarkupSafe==1.0
-mock==2.0.0
 monotonic==1.4
 mox3==0.25.0
 msgpack==0.5.6