diff --git a/erpnext/accounts/doctype/sales_invoice/test_sales_invoice.py b/erpnext/accounts/doctype/sales_invoice/test_sales_invoice.py
index 5e9c799fb86..c5b907685e8 100644
--- a/erpnext/accounts/doctype/sales_invoice/test_sales_invoice.py
+++ b/erpnext/accounts/doctype/sales_invoice/test_sales_invoice.py
@@ -64,6 +64,28 @@ class TestSalesInvoice(FrappeTestCase):
 		)
 		frappe.db.set_single_value("Accounts Settings", "acc_frozen_upto", None)
 
+	@change_settings(
+		"Accounts Settings",
+		{"maintain_same_internal_transaction_rate": 1, "maintain_same_rate_action": "Stop"},
+	)
+	def test_invalid_rate_without_override(self):
+		from frappe import ValidationError
+
+		from erpnext.accounts.doctype.sales_invoice.sales_invoice import make_inter_company_purchase_invoice
+
+		# frappe.get_cached_doc("Company", "_Test Company")
+		si = create_sales_invoice(
+			customer="_Test Internal Customer 3", company="_Test Company", is_internal_customer=1, rate=100
+		)
+		frappe.get_cached_doc("Customer", "_Test Internal Customer 3")
+		pi = make_inter_company_purchase_invoice(si)
+		pi.items[0].rate = 120
+
+		with self.assertRaises(ValidationError) as e:
+			pi.insert()
+			pi.submit()
+		self.assertIn("Rate must be same", str(e.exception))
+
 	def tearDown(self):
 		frappe.db.rollback()
 
@@ -4441,6 +4463,7 @@ def create_sales_invoice(**args):
 	si.conversion_rate = args.conversion_rate or 1
 	si.naming_series = args.naming_series or "T-SINV-"
 	si.cost_center = args.parent_cost_center
+	si.is_internal_customer = args.is_internal_customer or 0
 
 	bundle_id = None
 	if si.update_stock and (args.get("batch_no") or args.get("serial_no")):
@@ -4643,6 +4666,12 @@ def create_internal_parties():
 		allowed_to_interact_with="_Test Company with perpetual inventory",
 	)
 
+	create_internal_supplier(
+		supplier_name="_Test Internal Supplier 3",
+		represents_company="_Test Company",
+		allowed_to_interact_with="_Test Company",
+	)
+
 
 def create_internal_supplier(supplier_name, represents_company, allowed_to_interact_with):
 	if not frappe.db.exists("Supplier", supplier_name):