Mozilla Firefox has a new default search....Yahoo!

Mozilla will make Yahoo the default search engine in the Firefox browser as part of a five-year deal, the two companies announced Wednesday.

The partnership will make bring Yahoo search to Mozilla's desktop and mobile Web browsers in the United States, beginning in December. The financial terms of the deal were not disclosed.

Mozilla has used Google as its default global search provider in Firefox for a decade but is now opting for "a more local and flexible approach to increase choice and innovation on the Web, with new and expanded search partnerships by country," the company said.

In addition to Yahoo in the U.S., Mozilla is tapping Yandex Search for Russian Firefox users and is continuing to use Baidu in China. Firefox users around the world will still be able to use alternate, built-in search options in the browser—in the U.S., for example, Google, Bing, DuckDuckGo, eBay, Amazon, Twitter, and Wikipedia will continue to be supported, the company said.

Yahoo CEO Marissa Meyer said search has been "an area of investment and opportunity" for the company in recent years.