diff --git a/setup.py b/setup.py
index 72c19735..e959ec9f 100644
--- a/setup.py
+++ b/setup.py
@@ -66,7 +66,7 @@ install_requires = [
     'itsdangerous',
     'pytz',
     'sphinx',
-    'six',
+    'six>=1.11.0',
     'oauthlib',
     'unidecode',
     'jsonschema',