diff --git a/erpnext/accounts/doctype/purchase_invoice/purchase_invoice.js b/erpnext/accounts/doctype/purchase_invoice/purchase_invoice.js
index 2bd39a5..8835089 100644
--- a/erpnext/accounts/doctype/purchase_invoice/purchase_invoice.js
+++ b/erpnext/accounts/doctype/purchase_invoice/purchase_invoice.js
@@ -136,7 +136,7 @@
 
 		if (!doc.is_return && doc.docstatus == 1) {
 			if (doc.outstanding_amount >= 0 || Math.abs(flt(doc.outstanding_amount)) < flt(doc.grand_total)) {
-				this.frm.add_custom_button(__("Return / Debit Note"), this.make_debit_note, __("Create"));
+				this.frm.add_custom_button(__("Return / Debit Note"), this.make_debit_note.bind(this), __("Create"));
 			}
 		}