Demi Lovato had a few chuckles at Christina Aguilera's expense.

The 'X Factor' judge poked fun at 'The Voice' coach in a Keek video that served as a hilarious, unofficial promo for the Fox series.

The video features a classic photo of Aguilera belting out one of her tunes, but with Lovato's mouth superimposed onto the graphic. Lovato does a send up of Aguilera's infamous vocal runs to the tune of 'Ain't No Other Man,' singing the praises of 'X Factor' in the most literal sense.

Lovato captioned the clip with, "Christina, you are so sweet! Thank you so much for supporting the 'X Factor!'" It was a cute and surprisingly well-executed parody of Aguilera's notorious powerhouse pipes. Lovato does a killer impression!

And it may be necessary, too. Entertainment Wise reports that 'X Factor' is still lagging way behind 'The Voice' in terms of ratings, and sources say that Fox may pull the plug on the struggling singing competition show at the end of this season -- which would free Simon Cowell to return to the U.K. version of the show, which is still a hit.