diff --git a/erpnext/support/doctype/maintenance_schedule/maintenance_schedule.py b/erpnext/support/doctype/maintenance_schedule/maintenance_schedule.py
index 9efcf42..2fcd200 100644
--- a/erpnext/support/doctype/maintenance_schedule/maintenance_schedule.py
+++ b/erpnext/support/doctype/maintenance_schedule/maintenance_schedule.py
@@ -9,7 +9,7 @@
 from frappe.model.bean import getlist
 from frappe import throw, _
 from erpnext.utilities.transaction_base import TransactionBase, delete_events
-from stock.utils import get_valid_serial_nos
+from erpnext.stock.utils import get_valid_serial_nos
 
 class DocType(TransactionBase):
 	def __init__(self, doc, doclist=[]):