diff --git a/tox.ini b/tox.ini
index c5992726..c4a07780 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 toxworkdir = {env:TMPDIR:/tmp}/tox-{env:USER}/combo/{env:BRANCH_NAME:}
-envlist = coverage-py3-django111-pylint-{sqlite,pg},py3-django22-pg
+envlist = coverage-py3-django111-black-pylint-{sqlite,pg},py3-django22-pg
 
 [testenv]
 usedevelop = True
@@ -33,8 +33,10 @@ deps =
   vobject
   django-ratelimit<3
   git+https://git.entrouvert.org/debian/django-ckeditor.git
+  black: pre-commit
 commands =
   ./getlasso3.sh
   python manage.py compilemessages
   py.test {env:COVERAGE:} {posargs: --junitxml=junit-{envname}.xml tests/}
   pylint: ./pylint.sh combo/
+  black: pre-commit run black --all-files --show-diff-on-failure