diff --git a/tox.ini b/tox.ini
index d4e5595..e9ee42b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -10,8 +10,10 @@ install_command = pip install -U {opts} {packages}
 deps = -r{toxinidir}/doc/requirements.txt
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:docs]
+basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -W -b html doc/source doc/build/html