Spike Lee has said his decision not to attend the Oscars has been vindicated by the response from organisers.
The Academy Awards pledged to diversify its membership after complaints about the lack of ethnic diversity among this year's nominees.
The director said: "If a ruckus had not been raised, I believe the Academy would not have made those changes."
All 20 actors nominated this year for a best actor or supporting actor award are white.
In January, Lee - together with Will Smith and his wife Jada Pinkett-Smith - publicly said they would not attend the ceremony in protest.
Their comments prompted a number of high-profile Hollywood figures to join the debate and a social media campaign "Oscars So White" was launched.
In response, the Academy - which hands out the Oscar honours - announced it would double the number of women and ethnic minority members by 2020.
Academy president Cheryl Boone Isaacs said: "The Academy is going to lead and not wait for the industry to catch up.
"These new measures regarding governance and voting will have an immediate impact and begin the process of significantly changing our membership composition."
Actor Don Cheadle called the measures "a step in the right direction" while nominee Matt Damon added the industry had "a long, long, long way to go".
Discussing the controversy at the Berlin International Film Festival, Spike Lee said: "It was worth it. A week later they changed everything up."
"That would not have happened if people kept quiet."