London - England international brothers Mako and Billy Vunipola have both extended their contracts with Saracens, the English Premiership club announced on Wednesday.
Loosehead prop Mako, 24, joined Saracens from Bristol in 2011, with number eight Billy, 22, arriving from Wasps two years later.
Saracens did not disclose the length of their contracts, but said that the players had signed "multi-year extensions".
"I've been at the club a bit longer than my brother and I've really enjoyed my rugby and the club have really looked after me," Mako told the Saracens website.
"That's one of the key things for me. There are some really good people around me and I have some great friends here."
Billy added: "It was a very easy decision to remain at Saracens. I really enjoy being at the club. The environment really helps me with my rugby and also my time away from the game."
New Zealand-born Mako has won 20 England caps and made three appearances for the British and Irish Lions on their victorious 2013 tour of Australia.
Billy, who was born in Australia, has played for England 17 times and was named Best Forward at this year's Six Nations.
The pair follow England colleagues Owen Farrell, Brad Barritt and George Kruis in committing their futures to Allianz Park.
Director of rugby Mark McCall said: "We're delighted that Mako and Billy have extended their contracts with the club.
"The pair of them are both under 25, and they are the cornerstones of a very exciting pack of young forwards for this club. Alongside the likes of Jamie George, Will Fraser, George Kruis, Maro Itoje and Jackson Wray, Billy and Mako are playing a huge part going forward."