Kevin Kline will round out the cast of that ‘Hangover for the Metamucil crowd’ laffer, “Last Vegas”.

The flick, about four old-timers throwing a bachelor party in Vegas for the only one of them who has remained single, already has firm commitments from Michael Douglas, Robert De Niro, and Morgan Freeman.

While he’s terrific, can’t imagine Kline would’ve been the first choice for that fourth cast member – I suspect Jack Nicholson would’ve been atop of that list – but no doubt he’ll be a good fit nonetheless.

“National Treasure” helmer Jon Turteltaub is the director, which is a bit of a worry, but the screenplay is credited to Dan Fogelman, and he was behind “Crazy, Stupid Love” and “Tangled”, two absolute treats, so we should be good here.