diff --git a/doc/source/devref/development.environment.rst b/doc/source/devref/development.environment.rst
index 4d5a510b7b..920c109b25 100644
--- a/doc/source/devref/development.environment.rst
+++ b/doc/source/devref/development.environment.rst
@@ -84,7 +84,7 @@ Install the prerequisite packages.
 
 On Ubuntu::
 
-  sudo apt-get install python-dev libssl-dev python-pip git-core libxml2-dev libxslt-dev pkg-config libffi-dev libpq-dev libmysqlclient-dev libvirt-dev graphviz libsqlite3-dev
+  sudo apt-get install python-dev libssl-dev python-pip git-core libxml2-dev libxslt-dev pkg-config libffi-dev libpq-dev libmysqlclient-dev libvirt-dev graphviz libsqlite3-dev python-tox
 
 On Ubuntu Precise (12.04) you may also need to add the following packages::