diff --git a/tox.ini b/tox.ini
index e5023b21..f2a6efc9 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,35 +1,36 @@
 [tox]
 envlist=flake8,mypy,py3
 
 [testenv]
+extras =
+  testing
 deps =
   # the dependency below is needed for now as a workaround for
   #   https://github.com/pypa/pip/issues/6239
   swh.core[http] >= 0.0.75
-  .[testing]
   dev: ipdb
   pytest-cov
   pifpaf
 commands =
   pifpaf run postgresql -- \
     pytest \
   !dev: --cov {envsitepackagesdir}/swh/deposit --cov-branch \
         {envsitepackagesdir}/swh/deposit \
         {posargs}
 
 [testenv:flake8]
 skip_install = true
 deps =
   flake8
 commands =
   {envpython} -m flake8 \
     --exclude=.tox,.git,__pycache__,.tox,.eggs,*.egg,swh/deposit/migrations
 
 [testenv:mypy]
 setenv = DJANGO_SETTINGS_MODULE = swh.deposit.settings.testing
-skip_install = true
+extras =
+  testing
 deps =
-  .[testing]
   mypy
 commands =
   mypy swh