Flanker Dan Lydiate has agreed a new deal which will keep him at Ospreys until 2022.
The former Dragons back-row forward joined the Swansea-based region from French club Racing Metro in 2014.
Lydiate has been capped 64 times by Wales and and won three British and Irish Lions Test caps.
The 32-year-old missed most of last season due to injury but has been an ever-present for Ospreys during this campaign.
"Signing a new deal gives me security for my family," said Lydiate, "and I am looking forward to where the Ospreys are now heading.
'It's been a tough season, but hopefully we can get back to where we should belong and I want to be a part of it. "
Lydiate has captained the region this season whilst Justin Tipuric has been on Wales duty, but Ospreys have won just two of 12 Pro14 games and are bottom of Conference A.
They lost all six of their European Champions Cup games.
"It has been a really tough year, but I have enjoyed being captain while Tips has been away," he said.
"You do feel more responsible for the losses but I have been honoured to lead the boys out for every game I have this season.
"I still think I have a lot of rugby left in me in an Ospreys jersey. I have had a tough couple of years with injury and I am just enjoying playing back-to-back games."
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Ospreys recently agreed a fresh deal with Tipuric and have re-signed Welsh internationals Owen Watkin, Bradley Davies and Adam Beard in the past few weeks.
The region, who will have Toby Booth as their new head coach next season, have also lined up four newcomers in scrum-half Rhys Webb, full-back Mat Protheroe, prop Nicky Thomas and lock Rhys Davies.
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