diff --git a/frappe/core/doctype/doctype/doctype.py b/frappe/core/doctype/doctype/doctype.py
index 4a9c7f3135..d2d8d8a621 100644
--- a/frappe/core/doctype/doctype/doctype.py
+++ b/frappe/core/doctype/doctype/doctype.py
@@ -3,6 +3,8 @@
 
 from __future__ import unicode_literals
 
+import six
+
 import re, copy, os
 import frappe
 from frappe import _