MYSQL get last working day(friday) of previous month

select LAST_DAY('2013-12-09' - INTERVAL 1 MONTH) -
INTERVAL (CASE WEEKDAY(LAST_DAY('2013-12-09' - INTERVAL 1 MONTH))
          WHEN 5 THEN 1
          WHEN 6 THEN 2
          ELSE 0 END) DAY