diff --git a/tox.ini b/tox.ini
index 5db8361..aa2b6bf 100644
--- a/tox.ini
+++ b/tox.ini
@@ -40,6 +40,7 @@ deps =
   pylint-django<0.8.1
   django-webtest<1.9.3
   xmlschema<1.1
+  py2: enum34<=1.1.6
 commands =
   py.test {posargs: {env:COVERAGE:} {env:JUNIT:} tests/}
   coverage: ./pylint.sh atreal_openads/