Oprah Winfrey had to track down Nobel laureate Toni Morrison by calling her local fire department, the filmmaker behind a new documentary about the famed writer reveals.

Director of the “American Masters” episode “Toni Morrison: The Pieces I Am,” Timothy Greenfield-Sanders, told Page Six, “Oprah wanted to adapt her book ‘Beloved’ into a film but she didn’t have Toni’s phone number. So the only way of tracking her down was for her to get in touch with [Morrison’s] local fire department.”

But he said the late Pulitzer Prize-winning novelist, who died last year, didn’t react the way most people would upon getting a call from the Queen of All Media.

“The best part is, when Toni answered the phone, her initial reaction was not excitement. Toni asked [Oprah], ‘How did you get my number?’ ”

It ultimately worked out — Winfrey starred in the 1998 drama “Beloved” with Danny Glover and Thandie Newton, based on Morrison’s 1987 novel.

Greenfield-Sanders said his interview with Winfrey is one of the highlights of his film. He told us, “We waited for a year to do the interview and I am happy we did.”

The PBS doc will air Tuesday at 8 p.m.