Downgrading your iOS device to an older firmware is only possible if Apple is still signing the firmware you wish to downgrade to. Just a few weeks ago, Apple closed the signing window for iOS 9.3.2 and iOS 9.3.3 making it impossible to downgrade or upgrade to these firmwares manually via iTunes.

There’s also no legit tool that would allow you to downgrade a 64-bit device to a firmware that Apple isn’t signing. But a new teaser video surfaced today should give us some hope.

iOS hacker @tihmstar claims to be working on a new tool that would allow users to downgrade a 64-bit device from iOS 9.3.5 to an older firmware. In a video uploaded to YouTube, he can be seen using his partially-working tool called Prometheus to downgrade an iPhone 5s from iOS 9.3.5 to iOS 9.3.2. Needless to say, the downgrade completes successfully with the iPhone 5s returning to iOS 9.3.2.

There’s not enough information as to what the requirements of this tool are, but the developer does mention that Prometheus depends on APTickets and certain “other conditions” that he hasn’t been able to figure out yet. APTickets are the new form of SHSH blobs that will allow you to downgrade, only if you have saved them previously.

There’s no ETA as to when the tool will be released. As he explains, “releasing Prometheus now would be pointless, as it’s still in development and people don’t know how to use that overcomplicated tool.”

However, if this turns out to be legit and released to the public once completed, it will be the first ever tool to allow a 64-bit device to downgrade to an older iOS firmware.

If you own a device that is jailbroken, then we recommend you to stay on that firmware if you don’t wish to lose your jailbreak. Updating to iOS 9.3.5 means that you will lose your jailbreak entirely along with the ability to do so. There’s also no tool that will allow you to downgrade to iOS 9.3.3.

Are you excited about Prometheus? Let us know in the comments below.