Jaaskelainen told Sky Sports News, "Gary Megson told me in January, February time that he was going to offer me a new deal at the end of the season, so in my mind I have never thought about leaving.
"Whenever your contract comes to an end you always worry about what's going to happen, but the club came to me at the end of the season and everything was sorted in a week.
"Now it's ready for when I go back to Bolton to sign the deal.
"I'm absolutely delighted that I can carry on playing there.
"There's always competition (for places) - not only at Bolton - when you play in the top league if you don't perform there's going to be lots of other keepers coming in," he said.
"Of course Ali played very well at the end of last season and will be more impressive, but I think that will bring the best out of everyone."