President Donald Trump pushed back Sunday against a Fox News poll showing he’d lose to any of the top Democratic candidates in the 2020 election.

“There’s something going on at Fox, I”ll tell you right now, and I’m not happy with it,” the president told reporters at Morristown Airport in New Jersey, as he traveled back to the White House from his golf resort.

The poll, released Friday, indicated Trump would fall in a general election against former Vice President Joe Biden, Sen. Bernie Sanders (I-Vt.), Sen. Elizabeth Warren (D-Mass.), or Sen. Kamala Harris (D-Calif.). Trump’s margin of defeat ranged from 12 points against Biden to 6 points against Harris.

“I don’t believe it,” Trump said of the poll, according to a transcript released Sunday.

The U.S. leader, who has often treated Fox News as his go-to outlet, complained that his worst poll numbers have come from Fox. He singled out the channel’s political analyst Juan Williams for negative coverage, and predictably offered support for prime time hosts Sean Hannity and Tucker Carlson.

A Fox News poll in July showed Biden leading Trump by 10 points in a general election.