The former Leeds United fullback penned terms yesterday.
McDermott said, "It's a fantastic story, if you consider that two years ago Ian had been written off in certain quarters, and yet now he is a Premier League player again.
"That tells you everything you need to know about the person, the player, his resilience, his character, his determination and his quality.
"He still has that burning desire in training every day to play at the highest level. So I'm delighted that Ian has signed a new contract."