Britney Spears has been feeling a little blue lately -- and not in a bad way.
The pop star recorded a track for the upcoming film 'The Smurfs 2,' according to USA Today. The song, titled 'Ooh La La,' will be dubbed over the end credits of the movie, which is set to be released in July 2013.
"I have always loved the Smurfs as a kid and now my boys are the biggest Smurfs fans EVER," said the 31-year-old singer, in a press release. "I wanted to surprise them with a song in the movie."
The film is the sequel to 'The Smurfs,' the 2011 hit that grossed more than $560 million worldwide. Combining live action with animation, both films star Hank Azaria as the evil wizard Gargamel, who is bent on destroying the tiny, blue creatures called Smurfs.
"Remember that surprise song I recorded for my boys? It's coming soon! #OohLaLa for #TheSmurfs2 :) Stay tuned for more ..." the "Toxic" singer Tweeted on Wednesday.
The "surprise song" was produced and written by Joshua Coleman, Henry Walter and Lukasz Gottwald, who rose to fame in 2004 for Kelly Clarkson's "Since U Been Gone." Bonnie McKee and Jacob Kasher Hindlin also hold writing credits.
Singer Katy Perry will also be featured in the film -- not as a singer, but as the voice of Smurfette, who is kidnapped by the dastardly Gargamel in the sequel. In addition, the movie will feature the voice of the recently deceased comedian Jonathan Winters, who played the part of Papa Smurf.
"The Smurfs 2" will also feature the talents of Christina Ricci, Sofia Vergara, Neil Patrick Harris, Anton Yelchin, Alan Cumming, Brendan Gleeson, Jayma Mays, Fred Armisen and George Lopez. It will be in theaters on July 31, 2013.