Birmingham City have activated a one-year contract extension for defender Jonathan Grounds, the club have announced.
The 29-year-old's existing deal had been due to expire next month, but the extension means that he is now tied to the St Andrew's club until June 2018.
Grounds joined the West Midlanders on a free transfer from Oldham Athletic in the summer of 2014 and went on to establish himself under Gary Rowett.
Since making his Blues debut on the opening day of the 2014-15 Championship campaign away at Middlesbrough, he has gone on to make 140 appearances.
Grounds's extension comes on a busy day at Birmingham which also saw Tomasz Kuszczak commit his future to the club, the appointment of a new director of football in Jeff Vetere, and Harry Redknapp reportedly staying put as first-team manager.