diff --git a/frappe/custom/doctype/customize_form/customize_form.js b/frappe/custom/doctype/customize_form/customize_form.js
index e8eb4f3de4..ad18048554 100644
--- a/frappe/custom/doctype/customize_form/customize_form.js
+++ b/frappe/custom/doctype/customize_form/customize_form.js
@@ -97,6 +97,10 @@ frappe.ui.form.on("Customize Form Field", {
 			msgprint(__("Cannot delete standard field. You can hide it if you want"));
 			throw "cannot delete custom field";
 		}
+	},
+	fields_add: function(frm, cdt, cdn) {
+		var f = frappe.model.get_doc(cdt, cdn);
+		f.is_custom_field = 1;
 	}
 });