ExtJS5: Checkbox afterSubTpl wraps icon

The snippet below will not run on this site, but you can access a working demo here on JSFiddle.

I am trying to get the icon to appear to the right of the checkbox, but it appears to be wrapping. Is there a property that I need to set so that it will appear in-line? This worked in ExtJS4, but after I switched to ExtJS5 this does not work.

afterSubTpl Documentation

Ext.form.field.Checkbox -> config -> afterSubTpl

An optional string or XTemplate configuration to insert in the field markup after the subTpl markup. If an XTemplate is used, the component's render data serves as the context.

Code

Ext.require(['*']);

Ext.define('App.view.MainView', {
    extend: 'Ext.panel.Panel',
    xtype: 'mainView',
    alias: 'widget.mainview',
    title: 'Checkbox Template Example',
    referenceHolder: true,
    layout: {
        type: 'border'
    },
    initComponent: function () {
        var me = this,
            tooltip = me.getHelpIconWithTooltip();
        me.items = [{
            region: 'center',
            xtype: 'panel',
            title : 'A Panel Title',
            margin : 20,
            bodyStyle: 'padding: 8px;',
            layout : 'vbox',
            items : [{
                xtype: 'checkbox',
                fieldLabel : 'Checkbox',
                afterSubTpl: tooltip
            }]
        }],
        me.callParent();
    },
    
    getHelpIconWithTooltip: function () {
        return this.getFormIconWithTooltip('help-icon help-form-icon',
            'This is a help tooltip...');
    },

    getFormIconWithTooltip: function (iconClassList, toolTipText) {
        var getSpan = function(cl, qt) {
            return '<span class="'+cl+'" data-qtip="'+qt+'"></span>';
        }
        return [
            '<tpl>',
            getSpan(iconClassList, toolTipText),
            '</tpl>'
        ]; 
    }
});

Ext.define('App.app.App', {
    extend: 'Ext.app.Application',
    name: 'App',
    launch: function () {
        Ext.create('Ext.Viewport', {
            layout: 'fit',
            flex: 1,
            items: [{
                xtype: 'mainview'
            }]
        });
    }
});

Ext.onReady(function () {
    Ext.application('App.app.App');
});

.help-icon {
    display: inline-block;
    background: url(http://ift.tt/1zXWb2B) -705px -1125px no-repeat;
        width: 16px;
        height: 16px;
}

.help-form-icon {
    /*margin-left: 5px;*/
}

<link href="http://ift.tt/1zbKYsj" rel="stylesheet" />
<script src="http://ift.tt/1zbKYZh"></script>