Intel, comfortably the largest manufacturer of desktop processors, is no stranger to throwing its weight around to protect its core business. It has spent years fighting a massive $1.2 billion fine from the EU for violating anti-trust law to shut out AMD, its only real competitor.

Now, in a new blog post, Intel seems to be quietly warning companies like Microsoft and Qualcomm not to even think about using emulation to run proper Windows 10 on mobile-style processors.

Intel published a blog post that’s meant to celebrate 40 years of x86, the Intel-designed architecture that powers Intel’s CPUs, and allows Windows to run. Buried deep in the post is a not-very-veiled threat to any company thinking of making an emulator, which would let x86 software (like Windows 10!) run on a non-x86-processor, like Qualcomm’s Snapdragon mobile CPUs:

“Intel carefully protects its x86 innovations, and we do not widely license others to use them. Over the past 30 years, Intel has vigilantly enforced its intellectual property rights against infringement by third-party microprocessors…However, there have been reports that some companies may try to emulate Intel’s proprietary x86 ISA without Intel’s authorization…we do not welcome unlawful infringement of our patents, and we fully expect other companies to continue to respect Intel’s intellectual property rights.”

This is a direct response to an announcement that Microsoft and Qualcomm made at Computex two weeks ago. In the announcement, the companies said that support for Windows 10 on the Snapdragon 835 would be coming later this year, using emulator software. Asus, HP and Lenovo have all agreed to make devices using Qualcomm’s chipset, so this is no joke.

In theory, a Windows 10 PC running on Snapdragon would have much better battery life and efficiency than an x86 processor, which is why phones can last all day on a comparatively tiny battery. Intel knows this, and rather than trying to build a product to compete, it just wants to sit in the way and roadblock everything. Aren’t patents fun!