Update rename_field_max_days_allowed.py
diff --git a/erpnext/patches/v11_0/rename_field_max_days_allowed.py b/erpnext/patches/v11_0/rename_field_max_days_allowed.py
index 660e0ad..30b3ec3 100644
--- a/erpnext/patches/v11_0/rename_field_max_days_allowed.py
+++ b/erpnext/patches/v11_0/rename_field_max_days_allowed.py
@@ -1,4 +1,5 @@
 import frappe
+from frappe.model.utils import rename_field
 
 def execute():
 	frappe.db.sql("""