Apple’s new rules in the European Union mean browsers like Firefox can finally use their own engines on iOS. Although this may seem like a welcome change, Mozilla spokesperson Damiano DeMonte tells The Verge it’s “extremely disappointed” with the way things turned out.

“We are still reviewing the technical details but are extremely disappointed with Apple’s proposed plan to restrict the newly-announced BrowserEngineKit to EU-specific apps,” DeMonte says. “The effect of this would be to force an independent browser like Firefox to build and maintain two separate browser implementations — a burden Apple themselves will not have to bear.”

In iOS 17.4, Apple will no longer force browsers in the EU to use WebKit, the underlying engine that powers Safari. The change opens the door for other popular engines, such as Blink, which is used by Google Chrome and Microsoft Edge, as well as Gecko, the engine used by Firefox. It also means third-party browsers could become fully functional on iOS without any of the limitations that come along with WebKit.

Despite this, Mozilla argues that rolling out the changes only in the EU will make it more difficult for browsers to juggle different versions. “Apple’s proposals fail to give consumers viable choices by making it as painful as possible for others to provide competitive alternatives to Safari,” DeMonte adds. “This is another example of Apple creating barriers to prevent true browser competition on iOS.”