Liam Cooper has made his loan move from Hull City to Chesterfield permanent, penning a two-and-a-half year contract at the Proact Stadium.
The defender, who initially joined the Spireites on a month’s loan in November and had the deal extended into the New Year, joins from the npower Championship side for an undisclosed fee.
Cooper has been in impressive form since arriving from the Tigers, slotting in alongside captain Sam Hird in the heart of the defence.
The 21-year-old, whose loan was due to expire after Saturday’s game with Wycombe Wanderers, has made 11 appearances so far this season and notched two goals in the process.
Speaking about the deal, chief executive Chris Turner said: "It's a tremendous signing for us.
"Liam has the potential and ability to play at the highest level and we are delighted that he has chosen Chesterfield above other options.
"Paul Cook is now starting to shape the squad into what he requires."