Yale has been making smart locks for years now, but this week, it’s finally adding support for Apple’s HomeKit platform. Support starts out with just two locks, but they’re two of Yale’s more modern-looking models. They both unlock via PIN codes, and neither supports a traditional key.

Unfortunately, HomeKit support won’t just flip on. Yale has a sort of odd way of adding smart features to its locks that provides a lot of flexibility, but requires some work (and added cost) on customers’ part. Yale lock owners will have to buy a HomeKit module for $50, then open up their lock and plug the module in. It’s the same method Yale has used to add ZigBee and Z-Wave support (two other smart home connections) in the past.

At first, only Yale’s Assure Lock SL and Assure Lock Key Free Touchscreen will support the module, which goes on sale Monday. The rest of the Assure line will eventually add HomeKit support, but a representative for the company says they still have to clear Apple’s certification process.

Yale announced that it would be adding HomeKit support to its locks in January, saying that the modules would arrive in March. It’s not clear what accounts for the delay, but it seems like Apple’s testing process is making it all take even longer.