It’s been more than eight years since Heath Ledger’s tragic death — and in a new interview, his father, Kim, is educating people about the dangers of mixing drugs.

Talking to The Daily Mail, the elder Ledger says the Brokeback Mountain star was talking to his sister, Katie, who warned him about his dangerous habits right before his untimely death.

“His sister was on the phone to him the night before telling him not to take the prescription medications with the sleeping tablets,” Kim explains. “He said, ‘Katie, Katie, I’m fine. I know what I’m doing.’ He would have had no idea.”

To see what other stars said on their deathbeds, check out the gallery to see the final words of more celebrities.