diff --git a/tox.ini b/tox.ini
index 6a05c400d..3a60cf6a1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,6 +11,7 @@ setenv = VIRTUAL_ENV={envdir}
 deps = -r{toxinidir}/test-requirements.txt
 
 [testenv:linters]
+basepython = python3
 whitelist_externals = bash
 commands =
   bash -c "find {toxinidir}        \
@@ -22,10 +23,13 @@ commands =
   whereto {toxinidir}/doc/source/_extra/.htaccess {toxinidir}/doc/test/redirect-tests.txt
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:docs]
+basepython = python3
 commands = sphinx-build -W -b html doc/source doc/build
 
 [testenv:validate]
+basepython = python3
 commands = python3 tools/validate_tags.py