diff --git a/lower-constraints.txt b/lower-constraints.txt
index f35ff4ac5..04fb72384 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -29,7 +29,6 @@ jsonschema==3.2.0
 keystoneauth1==3.4.0
 linecache2==1.0.0
 mccabe==0.2.1
-mock==2.0.0
 monotonic==0.6
 mox3==0.20.0
 msgpack-python==0.4.0