Apple is reportedly using new proprietary software diagnostic tools to repair MacBook Pros and iMac Pros that, if not used on key part repairs, will result in an “inoperative system and an incomplete repair,” reads a document distributed to Apple’s Authorized Service Providers last month. A copy of the document was obtained by MacRumors and Motherboard today, both of which reported on the contents of the document and the apparent implications on third-party repair services.

It would seem that, without the proprietary software, third-party repair services will not be able to fix MacBook Pros that suffer from issues with the display assembly, the logic board, the keyboard and trackpad, and the Touch ID board, according to Motherboard. For iMac Pros, the lock will engage if you replace the logic board or flash storage. The computer won’t be usable again until Apple Service Toolkit 2, the name of the diagnostic tool, is used by a member of the company’s Authorized Service Provider program.

The measures are presumably there to ensure security. Apple’s proprietary chips have taken on increasing responsibilities over various functions inside the Mac, including storing secure enclave data and handling disc encryption. Especially on a day where hardware security is very much in the news, it seems reasonable to expect that Macs need to go through an Apple-approved diagnostic. But it’s also not traditionally how we like to think of PCs, which have historically not been sealed appliances. The Mac is apparently moving a little more in that direction. Apple did not immediately respond to a request for comment.

Tech critics and e-waste activists, however, claim that electronics makers are making devices hard to repair as a way to tightly control the repair market and encourage the purchase of new devices. Apple, alongside other hardware makers, has fought in recent years to prevent the passing of so-called right-to-repair laws that would force technology companies to make parts and instructions available to both users and third-party repair specialists. As it stands today, 19 states have proposed legislation regarding right-to-repair rules, but no state has passed a bill that would ban the use of, say, proprietary diagnostic tools.