WooCommerce: exclude category from catalog

add_filter( 'parse_query', 'custom_parse_query' );
function custom_parse_query( $q ) {

    if ( !$q->is_post_type_archive() ) return;
    elseif (!is_admin()){ //important
    $q->set( 'tax_query', array(array(
        'taxonomy' => 'product_cat',
        'field' => 'slug',
        'terms' => array( 'promocoes' ),
        'operator' => 'NOT IN'
    )));}

remove_filter( 'parse_query', 'custom_parse_query' );

}