If you don't cover up, you can't board. Air Canada's mask rule says travellers are required to wear face coverings, but a small number of people have been refusing to do so.
Air Canada told 680 News that there have been incidents where passengers would not wear masks, both before boarding and while on flights.
We have a graded approach, up to and including travel bans.
Due to this refusal, some people have been sanctioned for non-compliance.
The airline hasn't revealed exactly how many incidents have occurred, or exactly what each sanction was.
"Overall, however, our customers are generally respectful of each other and understand the importance of wearing facial coverings," Air Canada added.
Recently, Transport Canada closed a loophole that let people get away with not wearing masks in airports.