Issue with filter posts_join

In file: wp-includes/query.php
I find code :

if ( !$q['suppress_filters'] ) {
    $where = apply_filters_ref_array('posts_where', array( $where, &$this));
    $join = apply_filters_ref_array('posts_join', array( $join, &$this ) );
}

But is use :

add_filter('posts_join', 'custom_join_table');
function custom_join_table($join, $wp_query)
{
    //Do join
}

Warning : missing argument 2 for custom_join_table funtion.
Please help me how to get argument 2. (Do not use global $wp_query);