diff --git a/tox.ini b/tox.ini
index a16b831..cd2d136 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py37
+envlist = py36,py37
 
 # Define the minimal tox version required to run; if the host
 # tox is less than this the tool with create an environment and