diff --git a/requirements.txt b/requirements.txt
index 7f4fcec..de63b91 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -10,3 +10,4 @@ tempest>=17.1.0 # Apache-2.0
 oslotest>=3.2.0 # Apache-2.0
 mock>=2.0.0 # BSD
 monasca-common>=2.8.0 # Apache-2.0
+pytz>=2013.6 # MIT
diff --git a/tox.ini b/tox.ini
index f374acd..75230ac 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 minversion = 3.1.1
-envlist = py37,pypy,pep8
+envlist = py3,pypy,pep8
 skipsdist = True
 ignore_basepython_conflict = True