diff --git a/tox.ini b/tox.ini
index e3e86f4..44675d9 100644
--- a/tox.ini
+++ b/tox.ini
@@ -33,6 +33,7 @@ deps =
     django21: django>=2.1,<2.2
     django22: django>=2.2,<2.3
     djangomaster: https://github.com/django/django/archive/master.tar.gz
+usedevelop = True
 commands =
     coverage run --source=defender {envbindir}/django-admin.py test defender --settings=defender.travis_settings
     coverage report -m