Thatīs the code I see there
function wp_list_comments($args = array(), $comments = null ) {
global $wp_query, $comment_alt, $comment_depth, $comment_thread_alt, $overridden_cpage, $in_comment_loop;
$in_comment_loop = true;
$comment_alt = $comment_thread_alt = 0;
$comment_depth = 1;
$defaults = array('walker' => null, 'max_depth' => '', 'style' => 'ul', 'callback' => null, 'end-callback' => null, 'type' => 'all',
'page' => '', 'per_page' => '', 'avatar_size' => 32, 'reverse_top_level' => null, 'reverse_children' => '');
$r = wp_parse_args( $args, $defaults );
What should I change

Or I may have to add some code?