diff --git a/tox.ini b/tox.ini
index e1d093e46b72..1f38faf68e0b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,7 +7,7 @@ envlist = py38,functional,pep8
 ignore_basepython_conflict = True
 
 [testenv]
-basepython = python3.8
+basepython = python3
 usedevelop = True
 allowlist_externals =
 bash
@@ -344,7 +344,6 @@ commands =
 bindep test
 
 [testenv:lower-constraints]
-basepython = python3.6
 usedevelop = False
 deps =
 -c{toxinidir}/lower-constraints.txt
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<p><a href="http://altstyle.alfasado.net">AltStyle</a> によって変換されたページ <a href="https://opendev.org/openstack/nova/commit/c62616963aeefa4e090fca8eca15417210b99215.diff">(-&gt;オリジナル)</a>
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