Ulster second-row Johann Muller has agreed a one-year extension to his contract, the Irish club revealed on Tuesday.
The deal means that the South African, who joined Ulster from Natal Sharks on a two-year deal last summer, will remain in Belfast until June 2013.
Ulster secured a top-four finish in the Magners League this season but were beaten by Leinster in the play-off semi-final on Friday.
They also reached the Heineken Cup quarter-final stages for the first time since 1999 and Muller has been credited as the inspiration for much of the improvement at the club.
The 6ft 7in lock has stood in for Rory Best as captain on a number of occasions and started all but four of Ulster's competitive games.
'I'm delighted to extend my contract with Ulster Rugby by another year," he told the club's website www.ulsterrugby.com.
"I've really enjoyed my first season with Ulster, not only in terms of rugby but also personally.
"The people of Northern Ireland have been great to me and my family so staying an extra year wasn't a decision we had to think about for long."
Muller, who has been capped 23 times for the Springboks, said he was pleased with the club's progress this season.
But the 30-year-old, who celebrates his birthday in little over a fortnight, insisted there was still much work to do if Ulster hope to add some long-awaited silverware to their trophy cabinet.
'It was a successful season for us and we are taking steps in the right direction, he continued.
"But the players and the coaching staff need to keep working hard for next season. Teams are judged on silverware and we have nothing to show for our season.
"We are determined to win something for the trophy cabinet at Ravenhill next season and to do that we must keep improving.
"I've been in the fantastic position of having a leadership role within the squad. I hope I can keep trying to help the younger players and they keep improving.
"The more games they play and the more experience they get will be of benefit to themselves and Ulster.
"If, in a couple of years I leave Ulster and have managed to help a few players develop, I will be delighted with that."