After a six-year dry spell, Lindsay Lohan will end an apparent Letterman prohibition by appearing on 'The Late Show with David Letterman' on Tuesday, Apr. 9.

LiLo is set to promote her guest-starring appearance on Charlie Sheen's series 'Anger Management,' in which she plays a version of herself who's mandated to attend an anger management course taught by Sheen's character. (Hopefully art won't imitate life and leave her throwing feces at schools.)

Two years ago, Letterman was duped after being tricked into thinking Lindsay would be making a satellite appearance on the program. That never happened. But this time it's legit.

 
Lins should have no shortage of things to talk about. She's currently partying it up in Brazil before her upcoming 90-day rehab stint (and probably shoving generic Brazilian Adderall into her cheeks like a tweaked-out squirrel).