diff --git a/requirements.txt b/requirements.txt
index 1b3c7c5..d8a484d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -11,6 +11,7 @@ arrow
 backports.functools_lru_cache
 yandex.translate
 mutagen
+mock
 # forked repositories previously found at http://q-continuum.net
 git+https://code.manuelcortez.net/manuelcortez/libloader
 git+https://code.manuelcortez.net/manuelcortez/platform_utils