Millwall have agreed a deal to sign defender Shaun Williams from MK Dons for an undisclosed fee.
The 27-year-old, who has scored 10 goals in 33 appearances this season, will sign a two-and-a-half-year contract with the Lions.
"Shaun is going to be a big loss," Dons manager Karl Robinson told the club's official website.
"His contract was due to run out at the end of the season and although we offered him a new deal, he's decided to move on and we've got to respect that."
Williams, who is the Dons' current Player of the Year, will wear the number 17 shirt for Millwall.
