The European Union has reached an agreement to adopt the Digital Markets Act (DMA), a sweeping antitrust law meant to rein in Apple, Google, Meta and other tech giants. Lawmakers reached a “provisional” agreement on the law Thursday, following hours of negotiations, the European Parliament wrote in a statement.

The law could have far-reaching implications, some of which could extend beyond Europe. Most notably, one of the primary provisions of the DMA is that messaging providers would need to make their services interoperable with other services, “EU lawmakers agreed that the largest messaging services (such as Whatsapp, Facebook Messenger or iMessage) will have to open up and interoperate with smaller messaging platforms, if they so request,” the EU Parliament said following the agreement.

It’s unclear for now if this requirement would also apply to interoperability between the large messaging platforms themselves. Parliament wrote that the interoperability provisions for social networks “will be assessed in the future.”

In a statement, an Apple spokesperson said the company was “concerned” about some aspects of the law. “We remain concerned that some provisions of the DMA will create unnecessary privacy and security vulnerabilities for our users while others will prohibit us from charging for intellectual property in which we invest a great deal,” the spokesperson said. “We believe deeply in competition and in creating thriving competitive markets around the world, and we will continue to work with stakeholders throughout Europe in the hopes of mitigating these vulnerabilities.”

Meta didn’t immediately respond to a request for comment. The company’s head of WhatsApp, Will Cathcart, wrote on Twitter that he hoped the law was “extremely thoughtful.” “Interoperability can have benefits, but if it’s not done carefully this could cause a tragic weakening of security and privacy in Europe,” he said. 

The DMA also prohibits companies from “combining personal data for targeted advertising” without explicit consent, a move that could limit Meta and others’ ability to serve targeted ads to users. As The New York Times points out, there are still many questions about how European lawmakers will enforce these new rules and the companies in question are likely to raise legal challenges.

Earlier proposals of the law also included provisions that would change how Apple and Google ran their app stores. Under the proposed rules, Apple would have to allow users to install apps from other stores, and both Apple and Google would be required to allow developers to bypass their companies; storefronts and use their own billing. It’s unclear if those provisions were included in the latest agreement. The European Parliament will hold a press conference Friday, when they are expected to share more details.

Updated to include a comment from Will Cathcart.