The Air Canada Foundation is issuing a challenge to Canadians to bring a bit of extra joy to sick children this holiday season.

The campaign began with a tweet from Montreal Canadiens hockey player P.K. Subban on Tuesday. Recorded over the weekend during a sleepover event Air Canada held at Montreal Children’s Hospital, Subban recorded himself singing “Jingle Bells” (with some help from the kids there), and challenged the rest of Canada to do the same using the hashtag #CanadaCarols.

I’m bringing cheer with @AirCanada to sick kids for the holidays! Submit your version of Jingle Bells #CanadaCarols pic.twitter.com/Hc4McVdRRg

— P.K. Subban (@PKSubban1) December 15, 2015

A team from Air Canada followed up with their own response to P.K., who has been issuing challenges to other high-profile Canadians, including fellow NHL players, Prime Minister Justin Trudeau and Justin Bieber. Over the first two days of the campaign, the hashtag has been mentioned just under 2,000 times.

All of the submissions will be compiled into one video that will be shown to kids in pediatric hospitals across Canada on Christmas Eve. The hope is also that the campaign, which is being led by J. Walter Thompson Canada, will encourage Canadians to make donations to the Children’s Miracle Network of pediatric hospitals.

On the brand side, Air Canada launched its broader holiday campaign last week.