diff --git a/resources/requirements.txt b/resources/requirements.txt
index 40dc0328..3369e307 100644
--- a/resources/requirements.txt
+++ b/resources/requirements.txt
@@ -23,6 +23,7 @@ pythonpy
 readline
 ropemacs
 simplejson
+sphinx
 sqlalchemy
 tox
 vcrpy