diff --git a/lower-constraints.txt b/lower-constraints.txt
index e5ba65f59..216902741 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -41,7 +41,6 @@ lxml==4.1.1
 Mako==1.0.7
 MarkupSafe==1.0
 mccabe==0.2.1
-mock==2.0.0
 monotonic==1.4
 mpmath==1.0.0
 msgpack==0.5.6