The Dutch goalkeeper has performed impressively in the Premier League since joining the Swans from FC Utrecht last summer and has already been given the chance to extend his stay at the Liberty Stadium which currently runs until 2014.
"I was a little bit surprised Swansea City wanted to extend the contract already," he told De Telegraaf.
"I had a fantastic season, but when a new coach (Michael Laudrup) arrives you always have to wait to see what he thinks about you. However, he was enthusiastic.
"Swansea have stated that I am important for the future and the offer to extend until the summer of 2016 shows a lot of appreciation.
"When my agent, Wessel Weezenberg, returns from holiday the final details will be discussed. But we will definitely come together."