diff --git a/erpnext/manufacturing/doctype/work_order/work_order.py b/erpnext/manufacturing/doctype/work_order/work_order.py
index 5a6e6dbf55f..8846aae59d0 100644
--- a/erpnext/manufacturing/doctype/work_order/work_order.py
+++ b/erpnext/manufacturing/doctype/work_order/work_order.py
@@ -11,6 +11,7 @@ from frappe.query_builder.functions import Coalesce, IfNull, Sum
 from frappe.utils import (
 	cint,
 	flt,
+	get_datetime,
 	get_link_to_form,
 	now,
 	nowdate,
@@ -318,6 +319,10 @@ class WorkOrder(Document):
 		self.validate_subcontracting_inward_order()
 
 	def validate_dates(self):
+		if self.planned_start_date and self.planned_end_date:
+			if get_datetime(self.planned_end_date) < get_datetime(self.planned_start_date):
+				frappe.throw(_("Planned End Date cannot be before Planned Start Date"))
+
 		if self.actual_start_date and self.actual_end_date:
 			if self.actual_end_date < self.actual_start_date:
 				frappe.throw(_("Actual End Date cannot be before Actual Start Date"))