Typescript and Angular2-highcharts: Property 'series' does not exist on type 'Object'

In case someone finds it useful

Declare chart in your component like

export class DemoComponent {
  chart: Chart;

And add type option in series like

this.chart = new Chart({
  ...,
  series: [
    {
      name: 'Line 1',
      data: [1, 2, 3],
      type: 'line'
    }
  ]
});

In my case to make line chart working, I was using [runOutsideAngular]="true".

<highcharts-chart [Highcharts]="Highcharts" [options]="chartOptions.trends" [runOutsideAngular]="true"
            style="width: 100%; height: 300px; display: block;"
            [ngStyle]="{'opacity': chartOptions.trends.series[0].data.length === 0 ? 0 : 1}">
          </highcharts-chart>

this works fine in dev but while production it was throwing the same error

Property 'data' does not exist on type 'SeriesAbandsOptions'

casting chartOptions.trends to type any solved the issue.