diff --git a/erpnext/stock/doctype/serial_no/serial_no.json b/erpnext/stock/doctype/serial_no/serial_no.json
index a3d44af..6e1e0d4 100644
--- a/erpnext/stock/doctype/serial_no/serial_no.json
+++ b/erpnext/stock/doctype/serial_no/serial_no.json
@@ -1,7 +1,6 @@
 {
  "actions": [],
  "allow_import": 1,
- "allow_rename": 1,
  "autoname": "field:serial_no",
  "creation": "2013-05-16 10:59:15",
  "description": "Distinct unit of an Item",
@@ -434,10 +433,11 @@
  "icon": "fa fa-barcode",
  "idx": 1,
  "links": [],
- "modified": "2021-01-08 14:31:15.375996",
+ "modified": "2021-12-23 10:44:30.299450",
  "modified_by": "Administrator",
  "module": "Stock",
  "name": "Serial No",
+ "naming_rule": "By fieldname",
  "owner": "Administrator",
  "permissions": [
   {
@@ -476,5 +476,6 @@
  "show_name_in_global_search": 1,
  "sort_field": "modified",
  "sort_order": "DESC",
+ "states": [],
  "track_changes": 1
 }
\ No newline at end of file
diff --git a/erpnext/stock/doctype/serial_no/serial_no.py b/erpnext/stock/doctype/serial_no/serial_no.py
index 38291d1..2947faf 100644
--- a/erpnext/stock/doctype/serial_no/serial_no.py
+++ b/erpnext/stock/doctype/serial_no/serial_no.py
@@ -194,23 +194,6 @@
 		if sle_exists:
 			frappe.throw(_("Cannot delete Serial No {0}, as it is used in stock transactions").format(self.name))
 
-	def before_rename(self, old, new, merge=False):
-		if merge:
-			frappe.throw(_("Sorry, Serial Nos cannot be merged"))
-
-	def after_rename(self, old, new, merge=False):
-		"""rename serial_no text fields"""
-		for dt in frappe.db.sql("""select parent from tabDocField
-			where fieldname='serial_no' and fieldtype in ('Text', 'Small Text', 'Long Text')"""):
-
-			for item in frappe.db.sql("""select name, serial_no from `tab%s`
-				where serial_no like %s""" % (dt[0], frappe.db.escape('%' + old + '%'))):
-
-				serial_nos = map(lambda i: new if i.upper()==old.upper() else i, item[1].split('\n'))
-				frappe.db.sql("""update `tab%s` set serial_no = %s
-					where name=%s""" % (dt[0], '%s', '%s'),
-					('\n'.join(list(serial_nos)), item[0]))
-
 	def update_serial_no_reference(self, serial_no=None):
 		last_sle = self.get_last_sle(serial_no)
 		self.set_purchase_details(last_sle.get("purchase_sle"))