A choir of 15 British Airways employees showed some major holiday spirit by surprising travelers at London’s Heathrow Airport with impromptu Christmas caroling throughout the airport.

A cabin crew member kicked off the flashmob-like performance — which was captured posted to YouTube on Monday — by singing their version of “Deck the Halls" as she collected her checked luggage from the carousel. Other soloists then joined the song, including one cabin crew member who had just landed at Heathrow after working a flight.

The soloists then took their song from the baggage claim to the arrivals hall where the rest of the British Airways choir was waiting to finish caroling for the passengers in Terminal 5.

The video also showed pleasantly surprised passengers taking out their phones to capture the happy moment.

The choir took their holiday cheer very seriously as the performance was conducted by the current musical director for “Hamilton” on London’s West End, Richard Beadle and required weeks of rehearsals. He also rewrote the lyrics of the holiday classic to reflect travel with British Airways.

“I was amazed by the dedication and talent from the British Airways choir,” Beadle said in a statement. “Working in West End theatre, we are used to training sessions, followed by dress rehearsals, followed by live performances; it’s a very tiring process. Some of the British Airways choir swapped their day-jobs of flying a plane or servicing an aircraft, to performing in this choir, all without breaking a sweat.”

British Airways also shared a behind-the-scenes video of the group's rehearsals to their YouTube page.

Every year, British Airways creates a holiday video to celebrate the season, often with a stunt in Heathrow Airport. Last year, the airline flew four deserving kids to New York City for a luxe weekend modeled after Kevin McAllister in “Home Alone 2.”