Google isn’t the only company prepping a non-Webkit version of its browser, with Mozilla taking similar action.

News broke last week that Google was working on an iOS version of Chrome that used its own Blink rendering engine instead of Apple’s Webkit. App Store rules currently require all iOS web browsers to use Webkit, meaning that front-end features are the only thing that differentiate the options.

According to The Register, Mozilla is also working on a version of its browser that runs on its own Gecko rendering engine instead of Webkit.

Interestingly, while Mozilla and Google are not officially confirming it, it appears both companies may anticipate a future where regulation forces Apple to allow third-party browser engines on iOS. If such an eventuality occurs, both companies will be able to hit the ground running.