diff --git a/tox.ini b/tox.ini
index 588ef70..f143631 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,6 +7,6 @@ deps =
     pytest-cov
 commands =
     pip install -r requirements.txt
-    py.test --doctest-modules --cov=arachnado {posargs:arachnado}
+    py.test --doctest-modules --cov=arachnado {posargs:arachnado tests}