Scotland international Ruaridh Jackson will leave Wasps to join Harlequins at the end of the Aviva Premiership season.
The 28-year-old fly-half has made 16 appearances for Wasps after recovering from a ruptured anterior cruciate ligament and won his 28th international cap during this year's Six Nations.
"Ruaridh is a very talented player and we were obviously keen to keep him," Wasps director of rugby Dai Young told the club's official website.
"He was certainly part of our long-term plans, but we appreciate he was keen to secure the most game-time possible and felt this would be elsewhere given the 10s we will have here at Wasps next season.
"We will part on good terms and wish him the very best at Quins next season.
"Ruaridh is a great guy, who is extremely popular within the squad and is highly respected for his skill-set and his commitment to the team and to helping the squad succeed."
Jackson, who joined Wasps from Glasgow Warriors in 2014, said: "It was an extremely tough decision to leave Wasps having loved my two years here.
"It's a club on the up, playing great rugby, but I feel this move is the best decision for my career.
"I'd like to thank Dai especially for understanding my decision and letting me go, and wish the very best to everyone associated with the club."