The deal announced Wednesday runs through the 2018-19 season. It comes after the team agreed to a six-year extension with goalie Corey Crawford through 2019-20 on Monday.
Hjalmarsson helped the Blackhawks win their second Stanley Cup in four years last season, recording five assists and a plus-10 plus/minus rating in 23 playoff games.
A fourth-round draft pick by Chicago in 2005, Hjalmarsson has 56 points (9 goals, 47 assists) and a plus-48 rating in 306 career regular-season games to go with 17 points (one goal, 16 assists) in 75 playoff games.
Source: Associated Press