An irate straphanger hurled coins at an MTA worker on the subway in Brooklyn Tuesday morning, cops said.

The sleeping suspect lost it when he was woken up on the southbound 5 train in Flatbush — and started chucking the coins at the 66-year-old employee, according to police.

The worker, who wasn’t seriously injured, was treated by EMS at the scene for an injury to his forehead, police said.

The assailant took off at the Beverly Road stop, according to cops.