Hollywood, this is your wake-up call, courtesy of Haskell Wexler.

The iconoclastic cinematographer has been working for nearly a decade to alert the biz to the dangers of sleep deprivation. His self-financed doc “Who Needs Sleep?” bowed to strong reviews at Sundance and will be part of a one-hour report March 27 on CNN on sleep and health.

“This is all I’m working on now,” says Wexler, 83. “We’ve got to stop letting Hollywood sweep this under the rug.”

The issue became a cause nine years ago, when 35-year-old crew member Brent Hershman died in a car crash after working a 19-hour day on “Pleasantville.” That pic’s crew called for a 14-hour limit to workdays, dubbed “Brent’s Rule,” but found only limited success.

Wexler spent eight years on his doc, interviewing doctors and scientists who study sleep deprivation. Pic also includes interviews with Julia Roberts, Paul Newman, Tom Hanks, John Sayles, Sam Mendes, Billy Crystal, Annette Bening, Vittorio Storaro and Richard Zanuck.

Wexler says everyone who’s worked on a set understands the problem but reform has lagged because of multiple factors: government intransigence, guild inertia and corporate concerns over limiting management power and giving in to unions.

The WGA, which coordinated the filing of a pair of lawsuits last year by reality show writers over wage and overtime violations will host an April 4 screening of Wexler’s doc with speakers including WGA West prexy Patric Verrone, SAG prexy Alan Rosenberg, Lawrence Kasdan and members of Hershman’s crew.