diff --git a/tox.ini b/tox.ini
index c10917b..1676a2e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,9 +11,10 @@ basepython =
     py38: python3.8
     py39: python3.9
     pypy: pypy
-deps = -r{toxinidir}/tests/requirements.txt
 
-commands = py.test --basetemp="{envtmpdir}" --confcutdir=.. {posargs}
+setenv = PY_IGNORE_IMPORTMISMATCH=1
+deps = -r{toxinidir}/tests/requirements.txt
+commands = py.test --cov-append {posargs}
 
 [testenv:flake8]
 basepython = python3