diff --git a/tox.ini b/tox.ini
index 3fcabbf47e..d5530ba936 100644
--- a/tox.ini
+++ b/tox.ini
@@ -36,6 +36,9 @@ commands =
   bash -c '! find doc/ -type f -name *.json | xargs -t -n1 python -m json.tool 2>&1 > /dev/null | grep -B1 -v ^python'
 
 [testenv:functional]
+# TODO(melwitt): This can be removed when functional tests can be run
+# with python 3.x
+basepython = python2.7
 usedevelop = True
 setenv = VIRTUAL_ENV={envdir}
        OS_TEST_PATH=./nova/tests/functional