The overhead storage bins on WestJet's fleet of Boeing 737 aircraft would double as sleeper cabins, the Calgary-based airline announced in an April Fool's Day press release.

Travellers wishing to climb up on their chairs and snuggle up alongside their carry-on luggage would be charged $12, said the company.

"The overhead compartment has traditionally been a place where guests have placed their carry-on baggage," the airline said in its release. "Given that the overhead bins on our fleet are among the most spacious of any airline, we made the decision to offer sleeper cabins in that space."

Consumers were urged to contact WestJet to confirm availability and then were let in on the joke and offered a 10 per cent discount on travel booked before midnight.

In 2006, the company issued an April Fool's Day release saying that in a bid to aid with fuel efficiency, travellers would be asked to assume the "inflight winglet position" and spread their arms during takeoff.