A substitute teacher in Montville, New Jersey is now officially on the naughty list after telling a class of first graders that Santa isn't real.

Cedar Hill School sent out a letter to parents apologizing for the substitute's indiscretion, which occurred on Thursday.

"During the course of the day, a substitute teacher apparently announced to the class that Santa was not real," the school's principal, Michael J. Raj, wrote in a letter to local media outlets.

Raj did not identify the teacher, but did say he spoke to her "regarding her poor judgment in making this proclamation."

"As a father of four myself, I am truly aware of the sensitive nature of this announcement," Raj said, adding he was informing parents "so that you are aware of the situation and if the conversation comes up at home over the next few days you can take appropriate steps to maintain the childhood innocence of the holiday season."

There's no word if any type of disciplinary action was taken towards the teacher.