Mark Beevers has agreed to make his loan move to Millwall permanent when the transfer window reopens.
The Sheffield Wednesday defender has discussed personal terms at The Den and will sign a contract on January 1 next year.
"I'm delighted to be joining Millwall in January. Things have gone very well for me here during my loan spell here," he told the club's official website.
"The lads have made me very welcome, as have the fans and I'm looking forward to the next three years."
The 23-year-old has made 11 appearances for the Lions this season, featuring in defence alongside Danny Shittu.
