Forward Duncan Watmore has signed a two-and-a-half year extension to his contract with Middlesbrough, after impressing on a short-term deal.
The 26-year-old scored five goals in eight games for the Championship side, having signed terms in November.
Watmore, who left Sunderland last summer before moving down the A19, is on the shortlist for December's player of the month award.
"He gets on with the players and the staff," boss Neil Warnock said.
"He is really enjoying himself. He's a real good lad. We're looking forward to having him here on a longer-term basis now and hopefully seeing him score plenty more goals for the club.