diff --git a/erpnext/stock/doctype/item/item.py b/erpnext/stock/doctype/item/item.py
index aa51f47..aeab9ed 100644
--- a/erpnext/stock/doctype/item/item.py
+++ b/erpnext/stock/doctype/item/item.py
@@ -1062,3 +1062,7 @@
 		count+=1
 		if publish_progress:
 				frappe.publish_progress(count*100/len(variants), title = _("Updating Variants..."))
+
+def on_doctype_update():
+	# since route is a Text column, it needs a length for indexing
+	frappe.db.add_index("Item", ["route(500)"])