diff --git a/requirements/test.txt b/requirements/test.txt
index 7341f9d..99e28fa 100644
--- a/requirements/test.txt
+++ b/requirements/test.txt
@@ -1,6 +1,6 @@
 -r main.txt
 nose2
-mock
+mock==5.0.1
 coverage
 nose-cov
 hiro>0.1.6