Microsoft’s stringent policies around apps on Windows 10 S might prevent Google from bringing Chrome — the world’s most popular web browser — to the operating system. And if Google does ultimately decide to support the simplified version of Windows, it would require a much different app than the one desktop users are running today.

ZDNet has confirmed with Microsoft that “Windows Store apps that browse the web must use HTML and JavaScript engines provided by the Windows Platform.” On Windows, Chrome’s underlying code doesn’t currently use those engines.

Windows 10 S only allows users to install apps from the Windows Store, so this stipulation would seem to eliminate any possibility of Chrome being on the platform — unless Google reworks the browser to use Microsoft’s favored engines. Even then, users would be unable to pick Chrome as their default browser.

But Google has acquiesced in these situations before; the Chrome browser on iOS utilizes WebKit instead of Google’s Blink engine. It’s based on the same underlying foundation as Apple’s own Safari browser, but looks and feels like Chrome to the end user. If Google wants to put Chrome on Windows 10 S, it will need to resort to a similar solution. Should the company decide against that, Microsoft will certainly deal with complaints from consumers over Chrome’s absence. Google might opt to build a compatible version should Windows 10 S overcome potential confusion and find success. Even then, Chrome would always be a second-class citizen to Edge — just as it is to Safari on iPhones.

Microsoft is quick to point out that Windows 10 S customers have the option of upgrading to Windows 10 Pro for a more traditional and open app experience. Once they’ve paid the $49 fee, they can use any browser they’d like. Other operating systems like iOS and ChromeOS (the platform that Microsoft is directly competing against with Windows 10 S) have comparable rules in place.

And just like Apple and Google, Microsoft says the chief reason behind this policy is providing carefree security. “With this policy, instated early this year, the browser a customer chooses in the Store will ensure the protections and safeguards of our Windows platform.” The Verge has reached out to Google for comment on the company’s plans around Windows 10 S.