Last night, Apple released the first beta of iOS 9.3 to developers. The update brings quite a lot of new features including new 3D Touch options for some system apps, though the biggest new feature has to be Night Shift.

Apple does not mention anything about Night Shift’s compatibility in the iOS 9.3 developer release notes, but as it turns out, the feature will not be available on older iOS devices that are powered by a 32-bit chipset. This means that following iOS device owners will not be able to enjoy Night Shift once Apple commences the public roll out of iOS 9.3:

• iPhone 5
• iPhone 5c
• iPod touch 5G
• iPad mini
• iPad 2
• iPad 3
• iPad 4

All other newer iOS devices that will support Night Shift include:

• iPod touch 6G
• iPhone 5s
• iPhone 6
• iPhone 6s
• iPhone 6 Plus
• iPhone 6s Plus
• iPad Air
• iPad Air 2
• iPad mini 2
• iPad mini 3
• iPad mini 4
• iPad Pro
• iPhone SE
• 9.7-inch iPad Pro

As described by Apple, Night Shift automatically shifts the display color of your iOS device towards the warmer end of the spectrum to reduce exposure to bright blue light in the evening that can make it harder for one to fall asleep. iOS will do all of this automatically and without any user input by determining the sunset time in your location. The display will then be restored to its original color the next morning.

Read: How to Master Night Shift on Your iPhone and iPad

f.lux, a popular app that provides similar functionality as Night Shift, supports 32-bit iOS devices as well, but the app was shut down by Apple soon after its release late last year due to violation of Developer Agreement. The app used some private APIs and required users to sideload it using Xcode, which was against the terms and conditions set by Apple.

Read: How to get iOS 9.3’s Night Shift mode on your Mac right now

My recommendation to owners of older iOS devices that will not be getting the Night Shift feature with iOS 9.3, is to jailbreak their device and use one of the many similar apps built by the jailbreaking community.