diff --git a/requirements.txt b/requirements.txt
index b6ec5ec..0a9a36f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,5 +8,6 @@ unittest2==1.1
 zope.component==4.2.1
 configparser==3.5
 mozsvc==0.9
+futures==3.0
 https://github.com/mozilla-services/tokenserver/archive/1.3.0.zip
 https://github.com/mozilla-services/server-syncstorage/archive/1.6.13.zip