Did Zach Galifianakis (from "The Hangover") do a voiceover for the movie "Ratatouille"?

I saw "The Hangover" last night, and while it made me laugh hysterically, I couldn't help but be distracted by Zach Galifianakis' voice the whole time because I SWEAR he sounded just like the main character in the animated flick "Ratatouille." I can't find anything on IMDB or the internet that Zach did a voiceover for Ratatouille, but the voice is so distinctive I don't know how there could be more than one! Haha. Is Zach really *not* one of the voiceovers in Ratatouille???? Does anyone else agree with the similarity, or am I just crazy???? Thanks:)