diff --git a/erpnext/accounts/doctype/sales_invoice/test_sales_invoice.py b/erpnext/accounts/doctype/sales_invoice/test_sales_invoice.py
index 7cdb6df153e..cf752afc9d0 100644
--- a/erpnext/accounts/doctype/sales_invoice/test_sales_invoice.py
+++ b/erpnext/accounts/doctype/sales_invoice/test_sales_invoice.py
@@ -759,12 +759,11 @@ class TestSalesInvoice(unittest.TestCase):
 		self.assertRaises(SerialNoDuplicateError, si.cancel)
 		
 	def test_invoice_due_date_against_customers_credit_days(self):
-		si = create_sales_invoice()
 		# set customer's credit days
 		frappe.db.set_value("Customer", "_Test Customer", "credit_days_based_on", "Fixed Days")
 		frappe.db.set_value("Customer", "_Test Customer", "credit_days", 10)
 		
-		si.validate()
+		si = create_sales_invoice()
 		self.assertEqual(si.due_date, add_days(nowdate(), 10))
 		
 		# set customer's credit days is last day of the next month
diff --git a/erpnext/accounts/party.py b/erpnext/accounts/party.py
index 1f655df79ec..0bf014b4d66 100644
--- a/erpnext/accounts/party.py
+++ b/erpnext/accounts/party.py
@@ -164,7 +164,7 @@ def get_due_date(posting_date, party_type, party, company):
 	"""Set Due Date = Posting Date + Credit Days"""
 	due_date = None
 	if posting_date and party:
-		due_date = nowdate()
+		due_date = posting_date
 		if party_type=="Customer":
 			credit_days_based_on, credit_days = get_credit_days(party_type, party, company)
 			if credit_days_based_on == "Fixed Days" and credit_days: