diff --git a/tox.ini b/tox.ini
index a8ead27..9541926 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,7 +5,7 @@ skipsdist = True
 ignore_basepython_conflict = True
 
 [testenv]
-basepython = python3
+basepython = {env:TOX_PYTHON:python3}
 usedevelop = True
 setenv =
    VIRTUAL_ENV={envdir}
@@ -24,3 +24,9 @@ commands =
 
 [testenv:venv]
 commands = {posargs}
+
+[flake8]
+enable-extensions = H106,H203,H204,H205,H904
+show-source = true
+exclude = ./.*,build,dist,doc,*egg*,releasenotes
+import-order-style = pep8