Treemap label overlap

HTML

<script src="http://github.highcharts.com/a20dd76e/highcharts.js"></script>
<script src="http://github.highcharts.com/a20dd76e/modules/treemap.js"></script>
<div id="container"></div>

CSS

#container {
	min-width: 300px;
	max-width: 600px;
	margin: 0 auto;
}

JavaScript

$(function () {
    
    Highcharts.wrap(
        Highcharts.Legend.prototype, 
        'getAllItems', 
        function (proceed) {
    		return HighchartsAdapter.grep(
                proceed.call(this), function (item) {
                	return item.parent === undefined;
            	}
            );
    	}
    );
    
    
    $('#container').highcharts({
        series: [{
            type: "treemap",
            //layoutAlgorithm: 'stripes',
            alternateStartingDirection: true,
            levels: [{
                level: 1,
                layoutAlgorithm: 'sliceAndDice',
                dataLabels: {
                    enabled: true,
                    align: 'left',
                    verticalAlign: 'top',
                    style: {
                        fontSize: '15px',
                        fontWeight: 'bold'
                    }
                }
            }],
            data: [{
                id: 'A',
                name: 'Apples',
                color: "#EC2500"
            }, {
                id: 'B',
                name: 'Bananas',
                color: "#ECE100"
            }, {
                id: 'O',
                name: 'Oranges with a long name',
                color: '#EC9800'
            },{
                id: 'Kiwi',
                name: 'Kiwi',
                color: '#EC9800'
            }, {
                name: 'Anne',
                parent: 'A',
                value: 5
            }, {
                name: 'Rick',
                parent: 'A',
                value: 3
            }, {
                name: 'Peter',
                parent: 'A',
                value: 4
            }, {
                name: 'Anne',
                parent: 'B',
                value: 4
            }, {
                name: 'Rick',
                parent: 'B',
                value: 10
            }, {
                name: 'Peter',
                parent: 'B',
                value: 1
            }, {
            ...