Injuries curtailed his appearances in his first season with Ulster, but he became much more prominent in 2015–16,[7] making 23 appearances including 16 starts, scoring five tries and making 176 tackles.[8][1] He was selected for the 32-man Ireland squad to tour South Africa in June 2016.[9] In 2016–17 he made 27 appearances including 24 starts,[1] making 329 tackles and scoring four tries.[10] He was named Rugby Writers' Player of the Year in the 2017 Ulster Rugby Awards.[11] In 2017–18 he made 22 appearances including 18 starts, scoring four tries and making 196 tackles.[12] In 2018–19 he made 25 appearances including 16 starts, making 215 tackles and scoring one try.[13] He made his 100th appearance for Ulster in March 2019 against the Dragons.[2] In 2019–20 he made 19 appearances including 16 starts, scoring two tries.[1] In 2020–21 he made 19 appearances including 13 starts, scoring five tries and making 218 tackles and seven turnovers,[14] but missed the second half of the season with a shoulder injury that required surgery.[15] His opportunities in 2021–22 were limited, with seven appearances and two starts,[1] and he was released at the end of the season, to return to New Zealand.[16]