How to change option recently_edited?

The function is update_recently_edited in wp-admin/includes/misc.php. unfortunately it is fixed at 5:

function update_recently_edited( $file ) {
    $oldfiles = (array) get_option( 'recently_edited' );
    if ( $oldfiles ) {
        $oldfiles = array_reverse( $oldfiles );
        $oldfiles[] = $file;
        $oldfiles = array_reverse( $oldfiles );
        $oldfiles = array_unique( $oldfiles );
        if ( 5 < count( $oldfiles ))
            array_pop( $oldfiles );
    } else {
        $oldfiles[] = $file;
    }
    update_option( 'recently_edited', $oldfiles );
}