diff --git a/lower-constraints.txt b/lower-constraints.txt
index a371870c..dee819af 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -41,7 +41,6 @@ keystoneauth1==3.4.0
 linecache2==1.0.0
 MarkupSafe==1.0
 mccabe==0.2.1
-mock==2.0.0
 monotonic==1.4
 msgpack==0.5.6
 munch==2.2.0