The Hammers have not conceded in three of their last four away games, the most recent shutout coming on Sunday in a 3-0 win at Tottenham Hotspur in the Premier League.
Despite receiving praise for his performances in goal, Jaaskelainen believes that every player should be credited for the team's defensive efforts.
"It's definitely credit to the whole team because, if you look at the way we've been working for that, the team is giving us a base to win football matches," he told the club's official website.
"We have three clean sheets from four away matches and have only conceded one goal, so that's why we're getting points. Hopefully we can turn our home form and collect more points as well now."
West Ham continue their Premier League campaign on October 19 when they entertain Manchester City at Upton Park.