diff --git a/test-requirements.txt b/test-requirements.txt
index 2c18046..026ed73 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -1 +1 @@
-mock; python_version < '3.3'
\ No newline at end of file
+mock==2.0.0; python_version < '3.3'
\ No newline at end of file