diff --git a/tox.ini b/tox.ini
index 3d1a18c69..12452d6d3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,7 +7,7 @@ envlist = py26,py27,cover,lint
 
 [testenv]
 commands =
-    python setup.py develop easy_install letsencrypt[testing]
+    pip install -e .[testing]
     python setup.py test -q # -q does not suppress errors
 
 setenv =
@@ -16,12 +16,12 @@ setenv =
 [testenv:cover]
 basepython = python2.7
 commands =
-    python setup.py develop easy_install letsencrypt[testing]
+    pip install -e .[testing]
     python setup.py nosetests --with-coverage --cover-min-percentage=71
 
 [testenv:lint]
 # recent versions of pylint do not support Python 2.6 (#97, #187)
 basepython = python2.7
 commands =
-    python setup.py dev
+    pip install -e .[dev]
     pylint --rcfile=.pylintrc letsencrypt