diff --git a/tox.ini b/tox.ini
index 2503375..22580e6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,py36,py37,py38,py39
+envlist = py27,py36,py37,py38,py39,pypy,pypy3
 
 [testenv]
 deps =