diff --git a/lower-constraints.txt b/lower-constraints.txt
index 400d1eaa..698829dc 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -45,7 +45,6 @@ logutils==0.3.5
 Mako==1.0.7
 MarkupSafe==1.0
 mccabe==0.2.1
-mock==2.0.0
 monotonic==1.4
 mox3==0.25.0
 msgpack==0.5.6