diff --git a/erpnext/accounts/doctype/sales_invoice/sales_invoice.js b/erpnext/accounts/doctype/sales_invoice/sales_invoice.js
index 200fca6..d4d00ff 100644
--- a/erpnext/accounts/doctype/sales_invoice/sales_invoice.js
+++ b/erpnext/accounts/doctype/sales_invoice/sales_invoice.js
@@ -57,7 +57,7 @@
 				return item.is_delivered_by_supplier ? true : false;
 			})
 
-			if(Math.abs(flt(doc.outstanding_amount)) < flt(doc.grand_total)) {
+			if(doc.outstanding_amount >= 0 || Math.abs(flt(doc.outstanding_amount)) < flt(doc.grand_total)) {
 				cur_frm.add_custom_button(doc.update_stock ? __('Sales Return') : __('Credit Note'),
 					this.make_sales_return, __("Make"));
 				cur_frm.page.set_inner_btn_group_as_primary(__("Make"));