diff --git a/tox.ini b/tox.ini
index 98984dc..b6707e3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -23,7 +23,11 @@ sitepackages = True
 commands = flake8
 
 [testenv:cover]
-setenv = NOSE_WITH_COVERAGE=1
+commands =
+  coverage erase
+  find . -type f -name "*.pyc" -delete
+  python setup.py testr --coverage --testr-args='{posargs}'
+  coverage report
 
 [testenv:venv]
 commands = {posargs}