Change style of label when checkbox gets checked - Ionic 3

Hello... I have an ion-checkbox, and when it gets checked, it should change some style of an ion-label.

 <ion-label></ion-label>
 <ion-checkbox [(ngModel)]="item.checked" (ionChange)="check(item)" color="primary"></ion-checkbox>

When I click the checkbox, the ion-label associated with that checkbox should get:

 text-decoration: line-through;

And when it gets unchecked, the text-decoration should get normal again...

I've tried using ion-checkbox:checked in the SCSS, but it doesn't seem to work.

Any ideas on how to make this happen?