diff --git a/tox.ini b/tox.ini
index 3f55e7a..ce5f250 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,7 +4,6 @@ envlist = checkbuild
 skipsdist = True
 
 [testenv]
-basepython = python2.7
 install_command = pip install -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} -U {opts} {packages}
 setenv =
   VIRTUAL_ENV={envdir}
@@ -17,6 +16,7 @@ basepython = python3
 commands = {posargs}
 
 [testenv:checkbuild]
+basepython = python3
 setenv =
   IGNORE_GIT=1
 commands =