Issue with Bootstrap AdminLTE Checkbox not checkbox

I am using AdminLTE Bootstrap theme in my application and would like to keep a checkbox checked by default. I did the checked=checked also but that doesn't seem to work. Can anyone point out what I am doing wrong?

<div class="form-group">
    <label for="emailoptout" class="col-sm-2 control-label">Email Opt-Out</label>
    <div class="checkbox col-sm-4">
        <label><input type="checkbox" id="emailoptout" name="emailoptout" checked="checked"></label>
    </div>
</div>