No more late-night boozing on the LIRR.

Starting at midnight this morning, the Long Island Rail Road started banning alcohol on overnight weekend trains leaving Penn Station.

The ban is a pilot program meant to cut down on drunken passengers, vomit, and attacks on train crew members.

Six attacks on LIRR trains were reported last year, the highest in at least five years, officals said.

All trains out of Penn Station between midnight and 5 a.m. on Saturday and Sunday will be affected.

Passengers leaving at other times can still haul booze on board.