diff --git a/tox.ini b/tox.ini
index 9734b68..fcc6fc4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -12,6 +12,7 @@ setenv = VIRTUAL_ENV={envdir}
 deps = -r{toxinidir}/test-requirements.txt
 
 [testenv:linters]
+basepython = python3
 whitelist_externals = bash
 commands =
   bash -c "find {toxinidir}          \
@@ -28,6 +29,7 @@ commands =
             -print0 | xargs -0 yamllint"
 
 [testenv:pep8]
+basepython = python3
 usedevelop = False
 skip_install = True
 deps =
@@ -36,6 +38,7 @@ commands =
     pep8
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:docs]
@@ -57,6 +60,7 @@ whitelist_externals =
     reno
 
 [testenv:newnote]
+basepython = python3
 # Re-use the releasenotes venv
 envdir = {toxworkdir}/releasenotes
 deps = -r{toxinidir}/doc/requirements.txt