@ -140,7 +140,7 @@ class Alert extends Widget
Html::addCssClass($this->options, 'fade');
Html::addCssClass($this->options, 'in');
if ($this->closeButton !== null) {
if ($this->closeButton !== false) {
$this->closeButton = array_merge([
'data-dismiss' => 'alert',
'aria-hidden' => 'true',