TVGuide.com said the network placed the order because it was pleased with the ratings it has earned since its premiere this month.
The show is about a teacher who moves in with three male roommates after breaking up with her philandering boyfriend.
"We love the charming Zooey Deschanel and the entire cast, we're knocked out with the work that Liz Meriwether and the whole staff is doing and we are really psyched about the upcoming episodes in the pipeline," Kevin Reilly, Fox's president of entertainment, said in a statement. "It's great that audiences have responded so positively so far and we're confident that even more people will embrace the show -- and more comedy on Fox -- this season."
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