Joe Lewis has become Peterborough's record signing after joining from Norwich for £400,000.
The 20-year-old goalkeeper recently returned to Carrow Road after a successful loan stint at Morecambe, but found David Marshall and Matthew Gilks ahead of him in the pecking order.
He has now penned a four-and-a-half year deal with Posh and could make his debut in Saturday's League Two clash against Macclesfield.
"I feel that you don't get too many opportunities to make signings like this very often and I am delighted to sign such a highly-rated goalkeeper," Peterborough manager Darren Ferguson told the club's official website.
"Joe was outstanding in the two matches for Morecambe against us and he has tremendous potential."
Chairman Darragh MacAnthony added: "He was the gaffer's number one target in the transfer window and we went and broke our record to sign him.
"I have no doubt that he will be a massive success at Posh as we head towards the Premier League."
Brown in Preston talks
Chris Brown could be set to follow Lewis out of Norwich after opening talks with Championship rivals Preston.
The striker has scored just one goal in 14 appearances for The Canaries this season.
He is looking for a fresh challenge and is expected to have a medical with Preston on Tuesday, with the move possibly being completed this week.