In 2015, Lamur played in the first six games of the season, collecting 19 tackles, a shared sack, one pass defended and a special teams fumble recovery. In Week 2 against the San Diego Chargers, he recovered a muffed punt by Keenan Allen in the first quarter that set up a Bengals touchdown for a 7-0 lead. On October 11 against the Seattle Seahawks, he was credited with three tackles, and teamed with defensive end Carlos Dunlap to sack Seahawks quarterback Russell Wilson for an eight-yard loss on a third down situation late in the fourth quarter.