Add strikethrough to checked checkbox

I am trying to add strikethrough when i select a checkbox in my form (Bootstrap v3). I coded this bootply:

<div class="form-group ">
    <label for="inputName" class="col-md-1 control-label">select</label>  
    <div class="col-md-5">
        <div class="checkbox">
             <label><input type="checkbox" name="packersOff" class="strikethrough" value="1">sssssssss</label>
        </div>
     </div>
</div>

and added a class in css

.strikethrough:checked{
  text-decoration:line-through;
}

but it doesn't work..