diff --git a/tox.ini b/tox.ini
index 9b5c496..714e2de 100644
--- a/tox.ini
+++ b/tox.ini
@@ -28,7 +28,6 @@ deps =
     mypy
 setenv =
     {[testenv]setenv}
-    MYPYPATH={toxinidir}
 commands = mypy --config-file {toxinidir}/mypy.cfg toddlers tests
 
 [testenv:flake8]