Having signed a two-year contract extension with CBS just shy of his 65th birthday, David Letterman is showing no signs of slowing down any time soon -- but that doesn't mean he won't take some teasing about his newfound senior citizenship from other comedians.

On Monday night's "Late Show," Ricky Gervais brought Letterman a special birthday gift (and more than a few jokes about his "too old and crotchety to care" attitude). As for the gift, we're pretty sure Letterman won't be getting much use out of it (no matter how old he is). But hey, it's the thought that counts.

Watch the clip above and also hear Letterman gripe about certain people wanting him to go off the air. Turns out, his new contract has a stipulation that just might keep people watching out of sheer (albeit morbid) curiosity.

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