diff --git a/tox.ini b/tox.ini
index 60bfb1d97..4d8273576 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,15 +2,15 @@
 envlist = py26,py27,flake8
 
 [testenv]
-commands = nosetests
+commands = nosetests {posargs}
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 
 [testenv:cover]
-commands = nosetests --with-coverage
+commands = nosetests --with-coverage {posargs}
 
 [testenv:flake8]
-commands = flake8
+commands = flake8 {posargs}
 
 [testenv:venv]
 commands = {posargs}