The new deal will keep the centre-back at Derby County until the summer of 2014.
“I’ve had a great year and a half and I’m delighted the club see me as a big part of their plans,” the 28-year-old told the club website.
“We’ve made great progress this season and I’m confident we can build on that during the second half of the campaign and beyond.
“The club is run fantastically well from top to bottom… it was a no-brainer for me to put pen to paper.”
Manager Nigel Clough added: “Shaun has been one of our most consistent performers over the last year and he is just the type of character we want at the club.
“We want to keep hold of our best players and to have Shaun’s signature on the contract so soon after we started talking is a real feather in our cap.”
