diff --git a/tox.ini b/tox.ini
index 917b6a7..5704ec5 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,7 +11,7 @@ deps = -rrequirements.txt
 commands =
     py.test
     flake8 fimfarchive tests
-    mypy --ignore-missing-imports fimfarchive
+    mypy --ignore-missing-imports fimfarchive tests
 
 [pytest]
 addopts =