Donald Trump should be worried about a new documentary on him that has secretly been in the works for months, says filmmaker Michael Moore.

“Producers Harvey and Bob Weinstein announced Tuesday that they have secured worldwide rights to the film, which Moore had dubbed ‘Fahrenheit 11/9,'” the AP reports. “The name is taken from the day after the Nov. 8 election when Trump was declared the president-elect and is a reference to Moore’s 2004 President George W. Bush documentary ‘Fahrenheit 9/11.'”

Moore says the film will be explosive. In a statement, Moore said: “No matter what you throw at him, it hasn’t worked. No matter what is revealed, he remains standing. Facts, reality, brains cannot defeat him. Even when he commits a self-inflicted wound, he gets up the next morning and keeps going and tweeting.

“That all ends with this movie.”

The report notes that the filme will be shopped in Cannes, where “Fahrenheit 9/11” won the Palme d’Or.

The AP adds: “Moore released ‘Michael Moore in Trumpland,’ based on a one-man show of his, shortly before the November election. Moore premiered that film just days after shooting it. He released it in theaters and on various other platforms, all the while warning liberals that Trump was going to win the election.”