Last week, a good chunk of the digital world shut down and stopped working due to an update that caused Microsoft’s Windows operating system to crash and display a blue screen on millions of devices. This affected places like hospitals, schools, and airports. But one airline, unlike the others, was spared from the chaos.

And many are saying it’s because it’s still using an ancient operating system, but that’s not the case. On July 19, millions of computers and other Windows-powered devices crashed and stopped working around the globe. It was later discovered that Crowdstrike, a large cybersecurity company, had pushed out an update that was borked and broke everything for hours.

And as is common on the internet these days, people began joking about it and making up stories, some of which went viral. For example, a lot of people still think the Las Vegas Sphere crashed during the Crowdstrike event. ( It didn’t .

) But perhaps the most viral claim, which was reported by multiple outlets and shared online as the truth, was that Southwest Airlines in the United States avoided all of the Crowdstrike chaos because its systems still run on Windows 3.1. This isn’t accurate, though Southwest Airlines does indeed use some older software that it should probably upgrade.

Delta, United, American Airlines flights are all grounded right now. The reason Southwest is not affected is because they still run on Windows 3.1.

https://t.co/ezFubvKVNA — Artem Russakovskii (@ArtemR) July .