diff --git a/tox.ini b/tox.ini
index 7204dde..1bb6a06 100644
--- a/tox.ini
+++ b/tox.ini
@@ -21,3 +21,10 @@ deps =
 commands =
     coverage run --source=wideq -m unittest {posargs} discover -s tests
     coverage report
+
+[testenv:mypy]
+basepython = python3.7
+deps =
+    mypy
+commands =
+    mypy . --pretty