diff --git a/lower-constraints.txt b/lower-constraints.txt
index b210c0d..eb30354 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -18,7 +18,6 @@ jsonpointer==1.13
 keystoneauth1==3.4.0
 linecache2==1.0.0
 mccabe==0.2.1
-mock==2.0.0
 monotonic==0.6
 munch==2.1.0
 netaddr==0.7.18