These boxes earn the websites ad revenue, with Google acting as the broker. The European Commission said Wednesday morning that Google had for a decade illegally forced sites using the search box to give Google ads the greatest prominence on their results pages. The company also made its customers ask for its approval every time they wanted to change how competing search ads were displayed.

“Google has cemented its dominance in online search adverts and shielded itself from competitive pressure by imposing anti-competitive contractual restrictions on third-party websites. This is illegal under EU antitrust rules,” said Competition Commissioner Margrethe Vestager. “The misconduct lasted over 10 years and denied other companies the possibility to compete on the merits and to innovate—and consumers the benefits of competition.”

“We’ve always agreed that healthy, thriving markets are in everyone’s interest,” said Google global affairs chief Kent Walker in a statement. “We’ve already made a wide range of changes to our products to address the Commission’s concerns. Over the next few months, we’ll be making further updates to give more visibility to rivals in Europe.”

The new penalty comes on top of a $2.7 billion fine Google received in 2017 for disadvantaging other comparison-shopping providers on its results pages, and last year’s $5 billion fine for abusing its position in the Android ecosystem.

Google is appealing both those fines. But it’s also scrambling to appease the Commission over the issues that led to the previous penalties. After all, if Vestager’s office does not think Google has fixed the problems at hand, more fines may follow.

Late Tuesday, Walker said in a blog post that the company would ask its European Android users—both old and new—which browser and search apps they would like to use. One of the core issues leading to last year’s fine was Google’s tactic of forcing Android phone manufacturers to preinstall its search engine and Chrome browser.

Walker wrote that Google was doing “more to ensure that Android phone owners know about the wide choice of browsers and search engines available to download to their phones.”

This move is highly reminiscent of Microsoft’s “browser ballot” a decade ago, in which the software firm appeased EU antitrust officials by offering Windows users the choice to use rival browsers as soon as they fired up a new computer, rather than having to start with Microsoft’s Internet Explorer and then maybe switching to another browser if they got around to it.

Microsoft’s browser ballot was designed to stop the company using its operating-system monopoly to take over the web as well, and the principle beneficiary was, of course, Google, whose Chrome browser is now the most popular in the world. Thanks to Android’s success, Google is now in a similar position when it comes to mobile operating systems, and regulators want to stop it from using that position to shut out up-and-coming rivals.

“These latest changes demonstrate our continued commitment to operating in an open and principled way,” wrote Walker.

“We welcome the fact that Google is giving in to pressure from the EU antitrust authorities,” said Marc Al-Hames, the managing director of the privacy-oriented German search and browser firm Cliqz. “Whether this really will lead to fair competition depends on how the selection of browsers and search engines will look like.”

Google has also in the last week started showing European users new links to rival services in the product-comparison, job-search and local-business arenas, when users enter relevant search terms. Product comparisons were the focus of that first fine a couple years back, while the other two verticals have been widely tipped to be a focus for yet another antitrust probe against the company.

“All these are positive developments. Obviously, we will keep monitoring the market,” Vestager said of Google’s latest changes. “We’ve seen in the past that a choice screen can be an effective way to promote user choice. In the Google Android case, it has the potential to give users a real choice about what search and browser they want on their Android device.”

This article was updated to include Google’s statement.