diff --git a/requirements.txt b/requirements.txt
index 4df1e66100..6211c1cf6e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -22,6 +22,7 @@ requests
 SQLAlchemy
 tinycss2
 tldextract
+user-agents
 psycopg2-binary
 pusher_push_notifications
 pyenchant