BOSTON (CBS) – An MBTA worker who made the public address system his personal caroler on Christmas night will not face any serious punishment, a transportation spokeswoman told WBZ-TV Tuesday.

The unidentified employee typed in some of the lyrics to “Deck the Halls,” which were then scrolled across T information signs at the same time a robotic voice “sang” the song at the Park Street stop on the Red Line.

It ended up on Twitter.

Riders loved it.

On Monday, an MBTA spokesman said the T planned to punish the employee when he went back to work Tuesday, “for entering an unauthorized message into the customer information system.”

However, a spokeswoman for the Massachusetts Department of Transportation told WBZ-TV the worker was not suspended or fired and that the incident is a very minor infraction.

A written warning was put in his file.

The mystery dispatcher is said to be a longtime employee in good standing with the MBTA.