A high school student who was suspended for swearing in a conversation with a congressional staffer about gun control is asking for an apology from his school and his congressman.

On Monday, the American Civil Liberties Union of Nevada sent letters on behalf of 17-year-old Noah Christiansen to request Robert McQueen High School in Reno, Nevada, remove the record of his suspension and apologize to the student. The student’s punishment, they argued, amounted to an infringement on his First Amendment rights and could deter other students from reaching out to their representatives.

Christiansen got into trouble after the student walkout he participated in last Wednesday as part of a coordinated nationwide protest movement to demand solutions to school gun violence. Christiansen and his fellow students were marked tardy for walking out of class at 10:17 a.m. to mark the 17 people—mostly students—who were killed in a shooting at Marjory Stoneman Douglas High School in Parkland, Florida.

Christiansen told the Washington Post that during the walkout, his classmates passed around pieces of paper with phone numbers of legislators to call. Christiansen called the office of Rep. Mark Amodei, a pro-gun Republican, to complain, and reached a staffer in his office.

He told the Post that he said, “I believe bump stocks should be banned, the minimum age should be raised, and Congress people not already asking should get off their fucking asses and do something about gun control.”

The staffer thanked him for his comments, Christiansen said. But the school later told the student that staffer called the school to alert it to Christiansen’s use of “offensive” language. That afternoon, Christiansen was suspended for two days for “disrespectful behavior/language” and barred from assuming his role as the class secretary-treasurer, according to the ACLU.

Amodei, who told the Los Angeles Times he would review the protocol for taking calls from the public, defended his staffer, saying he wouldn’t apologize “because my guy accurately described what happened” and “he didn’t ask for any specific thing or beat the kid up,” he told the Nevada Independent.

“Welcome to the world where words have impact,” he told the Times.