Remove canonical from singular custom post types

gistfile1.txt

function remove_canonical() {
    if ( is_singular( 'voprosy' ) ||  is_singular( 'filialy') || is_singular( 'uslugi' )  ){
        add_filter( 'wpseo_canonical', '__return_false',  10, 1 );
    }
}
add_action('wp', 'remove_canonical');