Google’s Chrome OS just hit a major milestone, with Chromebook shipments outstripping Macs in the U.S. this year for the first time ever. The news comes just as Chrome OS is set to get support for Android apps and Google Play.

“Chrome OS overtook Mac OS in the US in terms of shipments for the first time in 1Q16,” IDC analyst Linn Huang told The Verge, adding that “Chromebooks are still largely a U.S. K-12 story.”

IDC doesn’t typically break down shipments based on individual operating systems in its report, which focuses on individual computer makers instead. However, we do know that Apple shipped just over 1.7 million Macs in the first quarter of 2016. So Chromebook shipments were presumably somewhere around 2 million units for the same three month period.

Apple is expected to unveil some major MacBook upgrades later this year, which could give the company a boost leading into the holiday shopping season. But Google’s Chrome OS is building momentum as well thanks to its low cost, attractiveness in the education sector and increasingly impressive hardware. It’s possible Apple could retake the lead over Chromebooks, but it definitely won’t be easy.