Updated

The Minnesota Vikings have signed defensive end Brian Robison to a four-year contract extension.

A person with knowledge of the deal tells The Associated Press it includes $12 million in guaranteed money. The person spoke on condition of anonymity because the team does not announce contract terms.

Robison says he is happy to get a deal done that keeps him where his career started. He was a fourth-round draft pick of the Vikings in 2007. He has 31 sacks in seven seasons and has solidified himself as one of the team's most consistent defensive players.

The deal adds a little bit of stability to the Vikings defensive line. Robison, defensive end Jared Allen and defensive tackle Kevin Williams all entered this season on the last year of their contracts.