The Academy of Motion Picture Arts and Sciences, organizer of the Oscar awards, pledged on Friday to double its membership of women and minorities by 2020 through an ambitious affirmative action plan that includes stripping some older members of voting privileges.

The announcement came amid a backlash over the absence of actors or filmmakers of color in this year's Oscars nominations, prompting actor Will Smith, director Spike Lee and a handful of others to say they plan to shun the Oscars ceremony on Thursday.

The membership rule changes, among the most sweeping in the academy's 88-year-old history, were unanimously adopted by the organization's Board of Governors on Thursday night, the group said in a statement. But the reforms will not affect voting for this year's Academy Awards.