Polymer Matrix Push 0.9 with Repeat Pattern

I am using Polymer 0.9 and I have this template.

<template>
    <ul>
        <template is="dom-repeat" items="{{menuPages}}">
            <li class="c-text">
                <span>{{item.title}}</span>
            </li>
        </template>
    </ul>
</template>

      

        
        
        
      

    

When I use this snippet to update the data, it doesn't load

    ready: function () {
        this.menuPages.push({title:'hey'});
        this.menuPages.push({title:'hey2'});
    }

      

        
        
        
      

    

However it works

    ready: function () {
        this.menuPages = [{title:'hey'}, {title:'hey2'}];
    }

      

        
        
        
      

    

Working example

Broken example