diff --git a/tox.ini b/tox.ini
index d20ce2b..eb73406 100644
--- a/tox.ini
+++ b/tox.ini
@@ -20,7 +20,8 @@ commands = {posargs}
 
 [testenv:cover]
 commands =
-  python setup.py test --coverage --coverage-package-name=grafana_dashboards
+  coverage erase
+  python setup.py test --coverage --coverage-package-name=grafana_dashboards --testr-args='{posargs}'
   coverage report
 
 [testenv:docs]