diff --git a/tox.ini b/tox.ini
index 274dcb4..044dd21 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,7 +8,7 @@ deps =
     click7: click>=7.0,<8.0
     click8: click>=8.0,<9.0
 commands =
-    coverage run --source={toxinidir}/sphinx_click -m unittest discover -s tests/
+    coverage run --source={toxinidir}/sphinx_click -m unittest {posargs}
     coverage report
 pip_pre =
     pre: true