Assign scope to modal when using Controller as

Hi, I’m having a problem when trying to assign a scope to my modal.

This is the way I’m doing my controllers:

(function () {
'use strict';

	.controller('Wallet', Wallet);

Wallet.$inject = ['$ionicModal'];

function Wallet($ionicModal) {
	var vm = this;

	vm.displayTransactionDetail = displayTransactionDetail;
	vm.hideTransactionDetail    = hideTransactionDetail;

	$ionicModal.fromTemplateUrl('app/accounts/transaction-detail.modal.html', {
		scope: null
	}).then(function (modal) {
		vm.modal = modal;

	function displayTransactionDetail(transaction) {;

	function hideTransactionDetail() {


I’m able to open the modal, but I can’t close it. In the code above I’m assigning a null scope, if I remove that line I’m still able to open the modal. Also I’m adding the controller in this way to my view (not the modal):

<ion-view view-title="Wallet balance" data-ng-controller="Wallet as vm">

Have you tried something like this? Any ideas?

Thanks in advance.