Enroth had been a restricted free agent, whose rights were retained by the team.
Enroth replaced Patrick Lalime as the Sabres' backup in the final half of last season. He was particularly effective filling in for an injured Miller late in the season, when he went 3-0-1 over five games to help Buffalo clinch a playoff berth.
Enroth finished with a 9-0-2 record, including a shutout, and a 2.73 goals-against average in 14 games last season.
The native of Sweden was Buffalo's second-round pick in the 2006 draft.
Lalime retired Wednesday and wasn't considered part of the Sabres' plans going into this season anyhow.