The Scot struggled to win a spot in the team in the early stages of the season, but has since emerged into a key player for the club.
"I hoped things would change and fortunately enough they did and now I am enjoying it," he told reporters at a press conference.
"No matter what age you are, after training in the week, you want to play on the Saturday. I didn't have that for a wee while and it was very frustrating.
"So to get back in the side was great. I'm happy to be getting a new deal and hopefully with the option, it will be for two years."
It is also understood that the 34-year-old's deal includes a further extension based on his number of appearances next season.