A group of about 30 mostly male students at Mullen High School, a private Catholic school in Denver, apparently haven’t received the memo that America has entered the 21st century.

During a basketball game against Overland High School last week, boys wearing Mullen shirts chanted derogatory remarks in unison, such as “Buckwheat” and “Shrimp Boat,” when Overland players stepped up to the foul line. Principal Greg Gotchey, who was at the game, heard some chanting in the first quarter and “immediately” told students to stop, but heard the epithets again later, according to The Denver Post, which adds that Gotchey will hold a forum tomorrow to discuss sensitivity.

Overland’s coach says he did not hear the chanting; otherwise, he would have removed his team from the court. A spokeswoman for Overland, a public school, however, calls the behavior of the Mullen students “despicable.”