diff --git a/api/controller/packages_unittest.py b/api/controller/packages_unittest.py
index fc71c60..1404a6a 100644
--- a/api/controller/packages_unittest.py
+++ b/api/controller/packages_unittest.py
@@ -7,6 +7,8 @@
 
 from __future__ import print_function
 
+import sys
+
 import mock
 
 from chromite.api.api_config import ApiConfigMixin
@@ -23,6 +25,9 @@
 from chromite.service import packages as packages_service
 
 
+assert sys.version_info >= (3, 6), 'This module requires Python 3.6+'
+
+
 class UprevTest(cros_test_lib.MockTestCase, ApiConfigMixin):
   """Uprev tests."""