diff --git a/tox.ini b/tox.ini
index d82c117..7a3ffcc 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,40 +1,45 @@
 [tox]
 envlist=flake8,mypy,py3-{core,db,server}
 
 [testenv]
+extras =
+  testing-core
+  core: logging
+  db: db, testing-db
+  server: http
 deps =
-  .[testing-core]
-  core: .[logging]
-  db: .[db,testing-db]
   db: pifpaf
-  server: .[http]
   cover: pytest-cov
 commands =
   db: pifpaf run postgresql -- \
     pytest --doctest-modules \
   slow: --hypothesis-profile=slow \
   cover: --cov={envsitepackagesdir}/swh/core --cov-branch \
   core: {envsitepackagesdir}/swh/core/tests \
   db: {envsitepackagesdir}/swh/core/db/tests \
   server: {envsitepackagesdir}/swh/core/api/tests \
     {posargs}
 
 [testenv:py3]
 skip_install = true
 deps = tox
 commands = tox -e py3-core-db-server-slow-cover -- {posargs}
 
 [testenv:flake8]
 skip_install = true
 deps =
   flake8
 commands =
   {envpython} -m flake8
 
 [testenv:mypy]
-skip_install = true
+extras =
+  testing-core
+  logging
+  db
+  testing-db
+  http
 deps =
-  .[logging,db,http,testing-core,testing-db]
   mypy
 commands =
   mypy swh