Czech Republic teenagers Filip and Patrik Twardzik have signed new contracts with Celtic.
The 19-year-old twins moved to the Scottish champions in 2009 following successful trial stints with the club.
Having impressed manager Neil Lennon with their performances in the youth and reserve teams, the duo have now committed their futures to the club for the foreseeable future.
"We've had so many years here so we didn't want to leave," Patrik told the club's official website. "We said want to stay because we've enjoyed it here.
"Our agent had conversations with the club and when the contract was finished we were pleased to sign it."
Filip added: "Three years is good for every player because it is not too long and not too short. I think this is what every player wants to have.
"We have learnt a lot since we have been here. The physical side changed a lot, but we are still the same players we have always been, our bodies have just progressed."
Filip has penned fresh terms until 2015, with his brother Patrik agreeing to another year in Glasgow.