diff --git a/tox.ini b/tox.ini
index c2e8af27..3a607283 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py35,py36,py37,py38,lint,docs
+envlist = py{35,36,37,38}-{linux,windows},lint,docs
 skip_missing_interpreters = true
 
 [gh-actions]
@@ -10,8 +10,10 @@ python =
     3.8: py38, lint, docs
 
 [testenv]
+platform = linux: linux
+           windows: win32
 deps=-rrequirements-test.txt
-extras=speedups
+extras = linux: speedups
 commands=
     coverage run setup.py test
     coverage report