--- a/tox.ini	Fri Mar 24 09:37:51 2017 +0100
+++ b/tox.ini	Wed Mar 22 14:36:05 2017 +0100
@@ -32,7 +32,7 @@
   sphinx
   -r{toxinidir}/requirements/doc.txt
 commands =
-  {envpython} -c 'import sphinx; sphinx.main()' -b html -d {envtmpdir}/doctrees .  {envtmpdir}/html
+  {envpython} -m sphinx -b html -d {envtmpdir}/doctrees .  {envtmpdir}/html
 
 [testenv:check-manifest]
 skip_install = true