After seeding developers with the OS X 10.11 El Capitan GM last week, Apple is now providing developers with the first build of OS X 10.11.1 beta for testing. The version features build number 15B17c compared to OS X 10.11 GM’s 15A282a.

Registered developers can find the OS update in the Developer Center. Updating from a previous OS X version requires downloading the OS X Software Update Seed Configuration Utility, then checking for the update in the Mac App Store’s Updates section. The update measures in at 606 MB. We’ll dig into the latest beta and report any notable differences between it and the OS X 10.11 GM.

The official OS X 10.11 El Capitan version for everyone is set to be released later this month on September 30th.

The OS X El Capitan 10.11.1 update improves the stability, compatibility, and security of your Mac.

Update: OS X 10.11.1 beta 1 includes the new set of emoji characters Apple first adopted with iOS 9.1 beta (including the middle finger). Full gallery here.