Adam Thompson has followed Ross Jenkins in committing his immediate future to Watford.
Earlier on Wednesday the Hornets confirmed that Jenkins, who had another year left on his existing deal, had signed a two-year contract extension to 2014.
And they later announced that Thompson, another home-grown player, had also committed himself to the Championship club until 2014.
The 18-year-old was a second-year scholar last season and after making his Carling Cup debut last August, he made his international debut for Northern Ireland in February - three days before his league bow for Watford.
The versatile defender, who first joined the club's academy in 2003, signed his first pro deal last November and finished the campaign with 11 appearances and one goal.
Jenkins was born in Watford and came through the club's academy before making his first-team debut in August 2008.
The 20-year-old went on to make 29 league appearances that season and 24 during the 2009/10 campaign.
After over three months out through injury last term, Jenkins returned to play 22 times as Watford finished 14th in the Championship.
Jenkins has made one appearance for England Under-20s and has now racked up 85 games for the Hornets, scoring twice.