diff --git a/tox.ini b/tox.ini
index e11c279f..cb4ba51b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,5 +7,6 @@ envlist = releasenotes
 install_command = pip install -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} {opts} {packages}
 
 [testenv:releasenotes]
+basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html