diff --git a/setup.cfg b/setup.cfg
index 1b3685b..f8be2cf 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -30,22 +30,19 @@ console_scripts =
     basicpy = basicpy:main
 
 [tox:tox]
-envlist = py38, flake8, black, pytest
+envlist = py38, py39
 isolated_build = True
 
-[testenv:flake8]
-deps = flake8
-commands =
-    flake8 src tests
-
-[testenv:black]
-deps = black
+[testenv]
+deps =
+    black
+    flake8
+    mypy
+    pytest
 commands =
     black --check --diff src tests
-
-[testenv:pytest]
-deps = pytest
-commands =
+    flake8 src tests
+    mypy src tests
     pytest tests
 
 [flake8]