diff --git a/erpnext/manufacturing/doctype/production_plan/production_plan.py b/erpnext/manufacturing/doctype/production_plan/production_plan.py
index 1e27e8d59de..937af0fac54 100644
--- a/erpnext/manufacturing/doctype/production_plan/production_plan.py
+++ b/erpnext/manufacturing/doctype/production_plan/production_plan.py
@@ -22,6 +22,7 @@ from frappe.utils import (
 )
 from frappe.utils.csvutils import build_csv_response
 from pypika.terms import ExistsCriterion
+from collections import defaultdict
 
 from erpnext.manufacturing.doctype.bom.bom import get_children as get_bom_children
 from erpnext.manufacturing.doctype.bom.bom import validate_bom_no