Sol Brynn has committed his future to the club by signing a new contract.
The 23-year-old has put pen to paper on a new four-year deal.
Boro-born Brynn has been with the club since the age of nine. He made his senior debut in our Carabao Cup clash against Leeds United earlier this season and has been a regular on the subs' bench.
The shot-stopper has had successful loan spells at Queen of the South, Swindon, and Leyton Orient.
Last season saw Brynn keep 13 clean sheets in 45 appearances for Orient before returning to Boro in the summer.