diff --git a/erpnext/patches/v13_0/update_amt_in_work_order_required_items.py b/erpnext/patches/v13_0/update_amt_in_work_order_required_items.py
index e37f291..64170ed 100644
--- a/erpnext/patches/v13_0/update_amt_in_work_order_required_items.py
+++ b/erpnext/patches/v13_0/update_amt_in_work_order_required_items.py
@@ -7,4 +7,6 @@
 	frappe.reload_doc("manufacturing", "doctype", "work_order")
 	frappe.reload_doc("manufacturing", "doctype", "work_order_item")
 
-	frappe.db.sql("""UPDATE `tabWork Order Item` SET amount = rate * required_qty""")
+	frappe.db.sql(
+		"""UPDATE `tabWork Order Item` SET amount = ifnull(rate, 0.0) * ifnull(required_qty, 0.0)"""
+	)