Rory Best has signed a contract extension with the Irish Rugby Football Union until the end of the 2019 Rugby World Cup.
The hooker captained Ireland to a Six Nations Grand Slam, which was completed with a 24-15 win over England at Twickenham on Saturday.
Ireland coach Joe Schmidt had joked Best was getting "faster and faster on the Zimmer frame" while discussing the 35-year-old's future.
Schmidt added that a decision on Best's future was "something that could come to fruition hopefully sooner rather than later" and it has now been resolved, with the Ulster man set to lead Ireland into the World Cup in Japan after putting pen to paper on a new contract.
"I am in a very privileged position as captain of Ireland and Ulster to be involved with two groups of incredibly talented players," Best said.
"I feel I can continue to make a contribution to both Ireland and Ulster Rugby and am delighted to have extended my IRFU contract to the next World Cup.
"Support of family, friends and supporters is a hugely important element for any professional sportsperson and I would like to thank everyone for their support, but specifically my wife Jodie who has been incredible and has ensured that as a family we have been able to share in all the great memories of the last few years."