diff --git a/erpnext/assets/doctype/asset/asset.js b/erpnext/assets/doctype/asset/asset.js
index 6b3f2c7..f6a7fa2 100644
--- a/erpnext/assets/doctype/asset/asset.js
+++ b/erpnext/assets/doctype/asset/asset.js
@@ -144,6 +144,10 @@
 			frm.set_df_property('purchase_invoice', 'read_only', 1);
 			frm.set_df_property('purchase_receipt', 'read_only', 1);
 		}
+		else if (frm.doc.is_existing_asset) {
+			frm.toggle_reqd('purchase_receipt', 0);
+			frm.toggle_reqd('purchase_invoice', 0);
+		}
 		else if (frm.doc.purchase_receipt) {
 			// if purchase receipt link is set then set PI disabled
 			frm.toggle_reqd('purchase_invoice', 0);
@@ -256,6 +260,7 @@
 	},
 
 	is_existing_asset: function(frm) {
+		frm.trigger("toggle_reference_doc");
 		// frm.toggle_reqd("next_depreciation_date", (!frm.doc.is_existing_asset && frm.doc.calculate_depreciation));
 	},