diff --git a/tox.ini b/tox.ini
index 0c8169a3aa424af5b5cc586a197e390fbd74fdc5..b6df1bfc1dc3e1f6033f6553942eb3fbd55e093f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,6 +5,7 @@ envlist =
   flake8
   mypy
   py3
+  pypy3
 
 [testenv]
 usedevelop = true