diff --git a/api/controller/sysroot.py b/api/controller/sysroot.py
index 4c21eca..25f712c 100644
--- a/api/controller/sysroot.py
+++ b/api/controller/sysroot.py
@@ -8,6 +8,7 @@
 from __future__ import print_function
 
 import os
+import sys
 
 from chromite.api import controller
 from chromite.api import faux
@@ -24,6 +25,10 @@
 from chromite.service import sysroot
 from chromite.utils import metrics
 
+
+assert sys.version_info >= (3, 6), 'This module requires Python 3.6+'
+
+
 _ACCEPTED_LICENSES = '@CHROMEOS'