diff --git a/api/controller/payload_unittest.py b/api/controller/payload_unittest.py
index d161b99..a0086aa 100644
--- a/api/controller/payload_unittest.py
+++ b/api/controller/payload_unittest.py
@@ -7,6 +7,8 @@
 
 from __future__ import print_function
 
+import sys
+
 from chromite.api import api_config
 from chromite.api import controller
 from chromite.api.controller import payload
@@ -16,6 +18,9 @@
 from chromite.lib.paygen import paygen_payload_lib
 
 
+assert sys.version_info >= (3, 6), 'This module requires Python 3.6+'
+
+
 class PayloadApiTests(cros_test_lib.MockTestCase, api_config.ApiConfigMixin):
   """Unittests for SetBinhost."""