function bbp_get_group_forum_ids( $group_id = 0 ) {

	// Assume no forums
	$forum_ids = array();

	// Use current group if none is set
	if ( empty( $group_id ) ) {
		$group_id = bp_get_current_group_id();
	}

	// Get the forums
	if ( ! empty( $group_id ) ) {
		$forum_ids = groups_get_groupmeta( $group_id, 'forum_id' );
	}

	// Make sure result is an array of ints
	$forum_ids = array_filter( wp_parse_id_list( $forum_ids ) );

	// Filter & return
	return (array) apply_filters( 'bbp_get_group_forum_ids', $forum_ids, $group_id );
}