The 38-year-old initially re-joined the club on a three-month deal in September as cover for Shay Given and Steve Harper, who were both struggling at the time. And the popular 'keeper is delighted to carry on.
Srnicek: "We have agreed that I will stay until the summer, then we will see.
"Maybe these are the last six months of my career, maybe not. I don't know. I would like to make some more appearances. But I did not expect to make any as I came here to cover my colleagues' backs. Then I appeared in two games.
"The first one was fantastic. The whole of St James' Park stood up and cheered my name. It was breathtaking. I can't even describe it, but I felt like I was in seventh heaven.
"If I don't get any more chances to play, I will not be unhappy. The two games have been something extra."