Sturrock said: "He is a very important player to us and it is very good to have this sorted out at this stage of the pre-season.
"I know how popular Kris is with our supporters and they will be delighted he has shown this commitment to the club.
"He came on in leaps and bounds last season and is a vastly improved player to the one who arrived at Home Park a year-and-a-half ago.
"The good thing is that I feel there is more to come from him, even more that he can add to his game, which is very pleasing."