diff --git a/tox.ini b/tox.ini
index c3230a2..6518618 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 [tox]
 toxworkdir = {env:TMPDIR:/tmp}/tox-{env:USER}/hobo/{env:BRANCH_NAME:}
-envlist = py3-django111-{hobo,multipublik,multitenant,schemas,authentic,passerelle},py3-django22-coverage-{hobo,multipublik,multitenant,schemas,authentic,passerelle}
+envlist = py3-django111-{hobo,multipublik,multitenant,schemas,authentic,passerelle},py3-django22-coverage-{hobo,multipublik,multitenant,schemas,authentic,passerelle},py3-black
 
 [testenv]
 usedevelop = True
@@ -56,6 +56,7 @@ deps:
 	xmlschema<1.1
 	enum34<=1.1.6
 	psycopg2-binary
+	black: pre-commit
 commands =
 	./getlasso3.sh
 	hobo: py.test {env:JUNIT:} {env:COVERAGE:} {env:NOMIGRATIONS:} {posargs:tests/}
@@ -64,3 +65,4 @@ commands =
 	multipublik: py.test {env:JUNIT:} {env:COVERAGE:} {env:NOMIGRATIONS:} {posargs:tests_multipublik/}
 	authentic: py.test {env:JUNIT:} {env:FAST:} {env:COVERAGE:} {env:NOMIGRATIONS:} {posargs:tests_authentic/}
 	passerelle: py.test {env:JUNIT:} {env:COVERAGE:} {env:NOMIGRATIONS:} {posargs:tests_passerelle/}
+	black: pre-commit run black --all-files --show-diff-on-failure