function bbp_add_pending_upgrade( $upgrade_id = '' ) {

	// Get the pending upgrades option
	$pending = bbp_get_pending_upgrades();

	// Maybe add upgrade ID to end of pending array
	if ( false === array_search( $upgrade_id, $pending, true ) ) {
		array_push( $pending, $upgrade_id );
	}

	// Update and return
	return update_option( '_bbp_db_pending_upgrades', $pending );
}