Excluding a Custom Post Type with a specific tag using pre_get_posts

Question

I have an archive page that lists a custom post type called 'event'. I have event posts with the tag 'regular', (the tag has an id of 53). I'd like to exclude these. I tried using pre_get_posts and then $query->set(('tag__not_in', array('53')) but I don't think tag__not_in will work with custom post types. Is there any way to fix this?

add_action( 'pre_get_posts', 'exclude_regular_tag');
function exclude_regular_tag( $query ){
    if ( is_admin() || ! $query->is_main_query() )
        return;
    if ( is_home() ) {
        return;
    }

    if ( is_post_type_archive( 'event' ) ) {
        $args = array('53'); //id of 'regular' tag in custom post type 'event'
        $query->set('tag__not_in', $args);
        return;
    }
}

Answer 1

I used tax_query instead of tag__not_in and it works now.

if ( is_post_type_archive( 'event' ) ) {

      $taxquery = array(
        array(
            'taxonomy' => 'event-tag',
            'field' => 'id',
            'terms' => array( 53 ), //the ID of the event tag
            'operator'=> 'NOT IN'
        )
    );

    $query->set('tax_query', $taxquery);
    return;
}