Washington ? You forgot to buckle up, dummy!

A commuter who put a homemade dummy in the passenger seat to sneak into the car pool lane was caught Wednesday near Seattle. But it wasn’t because a cop realized the passenger was fake.

Instead, the State Patrol trooper noticed the dangling belt buckle on the passenger side and suspected a seat belt violation.

Patrol spokeswoman Christina Martin told The Herald of Everett that the driver acknowledged trying to beat traffic by using the HOV lane.

He created his passenger by draping a rain jacket over plastic piping, topping it off with a Halloween mask of Gandalf, the “Lord of the Rings” wizard, a beard and a baseball cap.