Albion have converted Tim Krul's season-long loan from Newcastle into a permanent one-year deal.
The Dutch international initially arrived on a season-long loan last month, but has now signed a one-year contract.
He made his Brighton debut in last night's Carabao Cup defeat at Bournemouth. The deal means Krul ends a 12-year association with Newcastle, after arriving from Dutch side ADO Den Haag in the summer of 2005.
He has also played seven times for the Netherlands and won the Under-21 European Championships in 2007.
Albion are limited to a maximum of two loan signings from fellow Premier League clubs and currently have Izzy Brown on a season-long loan from Chelsea.