Aberdeen have confirmed the permanent signing of Mark Reynolds on a four-and-a-half year deal.
The defender had been on loan with the Dons from Sheffield Wednesday, and has now made his move permanent after leaving Hillsborough by mutual consent.
Chief executive Duncan Fraser told the club's official website: "The length of the deal reflects the fact the player very quickly established himself as part of the backbone of the squad here and, despite the fact he is still only 25, he is very much regarded as one of our senior players with a wealth of experience under his belt."
The deal sees him remain at Aberdeen until the summer of 2017, while goalkeeper Dan Twardzik has signed an 18-month contract after being granted international clearance.
Fraser said: "Jim Leighton rates the former Bayern Munich goalkeeper very highly and we are delighted to be able to tie this deal up."