diff --git a/tox.ini b/tox.ini
index 304cc973d..a126dbbf1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -139,7 +139,7 @@ commands =
 [testenv:regen]
 changedir = doc/en
 skipsdist = True
-basepython = python3.5
+basepython = python3.6
 deps =
     sphinx
     PyYAML