Ulster have announced new contracts for Irish internationals Luke Marshall, Rob Herring and Kieran Treadwell.
The trio have agreed three-year extensions, keeping them with the province until the summer of 2021.
Marshall, who is a product of the Ulster Academy, made his senior debut against Munster in October 2010.
Herring, who joined Ulster in 2012, and Treadwell, who moved to Belfast in 2016, were both capped by Ireland during the autumn international series.
“Luke has been one of our most consistent players in recent years; he’s a robust presence in our midfield and is a brilliant link man in both attack and defence,” Ulster’s director of rugby, Les Kiss said.
“He is a passionate about rugby in Ulster and I think that is evident not only in his performances on the pitch, but also in the way he contributes so positively to the local rugby community.”
South African-born Herring qualifies to play for Ireland through residency rules and scored a try during the record breaking 38-3 win over the Springboks on 11 November.
Treadwell represented England at U20 level but qualifies for Ireland through his Irish mother and made his Test debut during the summer tour to the USA and Japan in June.
“Rob and Kieran have also been in excellent form this season and I was delighted to see them earn recalls into the national squad for this month’s fixtures,” Kiss added.
“Rob has really grown as a player since his arrival at Ulster five years ago and he is widely regarded as a highly skilled hooker who leads from the front.
“Kieran has made a big impression over the past 18 months and it’s evident that he possesses all the attributes required to become a top class second row; he’s a big, mobile unit and is a good student of the game.”