CPT in Recent Post Widget

/**
 * Display CPT on Recent Post widget
 *
 * @version WP 4.6.1
 */
add_filter( 'widget_posts_args', 'knaeckebrot_widget_recent_post_4_cpt' );
function knaeckebrot_widget_recent_post_4_cpt( $params )
{
    $params['post_type'] = array( 'post', 'cpt01', 'cpt02');
    return $params;
}

Quelle: https://wordpress.stackexchange.com/questions/241060/display-custom-post-type-in-recent-posts