diff --git a/tox.ini b/tox.ini
index 41d757e19ed..d6697460639 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,10 +1,12 @@
 [tox]
 envlist = docs,py3,pep8
 minversion = 4.6.0
+ignore_basepython_conflict = True
 
 [testenv]
 description =
   Run unit tests.
+basepython = {env:TOX_PYTHON:python3}
 setenv =
   VIRTUAL_ENV={envdir}
   OS_LOG_CAPTURE={env:OS_LOG_CAPTURE:true}