Boeing's execs have been using the company's private jets for personal travel — and it's more than we thought.

Top Boeing executives used an additional $545,520 for personal jet travel in 2021 and 2022 than was initially reported, according to an amended SEC filing.

The Wall Street Journal reports Boeing made the revisions after an investigation last year into the use of private jets by its top executives.

The Journal found that, in some cases, personal trips had been improperly classified as business travel.

"Following a review commenced by the company in 2023, we found certain items, primarily aircraft, and ground transportation costs … were not previously classified as perquisites by the Company but should have been classified as such in accordance with SEC rules and guidance," the company said in its proxy statement.

The revised stats for Boeing's outgoing CEO, Dave Calhoun, amounted to an additional $142,315 in personal travel in 2021 and 2022.

That said, Boeing wrote in the filing that its CEO "is required to use company aircraft for all business and personal travel for security reasons."

The other execs whose travel was revised in the filing include CFO Brian West, former president and CEO of commercial airplanes Stanley Deal, and president and CEO of Boeing defense, space, and security Theodore Colbert.

Boeing did not immediately respond to a request for comment from Business Insider.

Calhoun recently said he would step down at the end of 2024 after he faced significant scrutiny following the Alaska Airlines 737 Max 9 door blowout in January.

The Journal notes there are tax implications when company jets are taken for personal travel and that the IRS said it will begin auditing corporate jet usage this year.

The Journal's 2023 investigation found that Boeing's fleet of private jets had made around 400 trips to or from airports near Calhoun's two homes in New Hampshire and South Carolina since roughly 2020 after Boeing moved its headquarters from Chicago to Arlington, VA., in 2022, and attempted to get staff to return to the office.