The video was reportedly taken at the request of a flight attendant while the late Glee star was en route from Japan to Vancouver, his final destination.
“I wanted to record this video for you guys just to let you know to stay out of trouble and stay in school,” the actor said in his now-eerie message.
Watch the full clip, above.
Monteith died late Saturday evening on the 21st floor at the Fairmont Pacific Rim Hotel in Vancouver, Canada. The cause of death was later determined to be an overdose of heroin and alcohol.
He was 31.