diff --git a/tox.ini b/tox.ini
index 379249d3..6e11ee3c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -3,6 +3,7 @@
 envlist=py{27,34,35,36}-pytest{29,30,31},py37-pytest{30,31}
 
 [testenv]
+download = true
 commands=
   pip install -U . # hande the install order fallout since pytest depends on pip
   py.test --confcutdir=. --junitxml={envlogdir}/junit-{envname}.xml []