A substitute teacher in Montville has landed on the naughty list after telling first-graders that Santa isn't real.

The Cedar Hill School sent a letter to parents apologizing for the holiday gaffe, which occurred on Thursday in the first-grade class.

"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 the letter provided Friday to NJ Advance Media.

Raj did not identify the teacher, but said he had spoken with her "regarding her poor judgement 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."

Montville Schools Superintendent Rene Rovtar issued a statement that she was "troubled and disheartened by this incident."

"The childhood wonder associated with all holidays and traditions is something I personally hold near and dear in my own heart," Rovtar said.

Rob Jennings may be reached at rjennings@njadvancemedia.com. Follow him on Twitter @RobJenningsNJ. Find NJ.com on Facebook.