diff --git a/tox.ini b/tox.ini
index dd3e4b50..a759504a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -10,8 +10,9 @@ envlist =
 skipsdist = True
 
 [testenv]
+sitepackages = True
 setenv =
-	PYTHONWARNINGS = all
+    PYTHONWARNINGS = all
 deps =
     -r{toxinidir}/requirements.txt
     coverage