Apple has released the first iOS 9.2.1 beta to developers for testing on iPhone, iPad, and iPod touch. The new software version features build number 13D11 which compares to last week’s iOS 9.2 release at 13C75. The update is available for registered developers currently through the iOS Dev Center.

The first iOS 9.2.1 update likely includes further bug fixes and performance improvements after last week’s public iOS 9.2 release. That new version included a long list of under-the-hood tweaks plus a few public facing features including more 3D Touch support in iBooks, better support for Classical music in Apple Music, Arabic Siri, and support for Apple’s Lightning to SD Card Reader adapters, both new and old.

We’ll check out the new iOS 9.2.1 beta and update with any notable changes. The update does not appear to be available over-the-air, instead requiring using the Developer Center to install. Public beta test versions typically follow after a day or so with first releases, but let us know if you’re a public beta tester and see the update.