Yahoo said Chief Executive Marissa Mayer faced “specific security threats” in 2015 — and the company accordingly spent more than a half-million dollars on her personal security.

Last year’s tab came to $544,061 — more than 20 times the $26,891 Yahoo had spent a year earlier on protecting Mayer and her immediate family, according to a Monday filing.

“During 2015 Ms. Mayer faced specific security threats that we believed were credible,” Yahoo said in the filing. The company didn’t elaborate on the threats.

By comparison, Facebook said last month it spent $6.5 million on bodyguards and other security for its CEO, Mark Zuckerberg.

Apple, meanwhile, spent just $275,000 on security for CEO Tim Cook.

Yahoo said it doesn’t consider the security tab a “perk,” and said it “is especially reasonable in light of the fact that Ms. Mayer does not ask the company to reimburse her private aircraft costs for business travel.”

Mayer last year also earned a cash bonus of $1,125 under Yahoo’s “Invention Recognition Award” program, open to all full-time employees, for “being among the inventors named in a pending patent application” filed by the company, Yahoo said.