The director of the Auschwitz Memorial appealed to Nigeria’s president on Friday to pardon a 13-year-old boy who was sentenced to 120 months of prison on blasphemy charges, even volunteering to serve part of the boy’s sentence.

Piotr Cywinski wrote to Nigerian President Muhammadu Buhari about the case of Omar Farouq, who was recently convicted in a Sharia court in Kano State in northwest Nigeria after he was accused of using blasphemy in an argument with a friend.

Cywinski said that as the director of the site that preserves the remains of the German Nazi extermination camp, “where children were imprisoned and murdered, I cannot remain indifferent to this disgraceful sentence for humanity.”

Cywinski said that if the president couldn’t give clemency, he would suggests that 120 adult volunteers from all over the world — “myself personally among them” — each serve a month in a Nigerian prison.

“Regardless of what he said, he cannot be treated as fully aware and responsible, given his age,” Cywinski wrote. “He should not be subjected to the loss of the entirety of his youth, be deprived of opportunities, and stigmatized physically, emotionally, and educationally for the rest of his life.”

The Auschwitz memorial site is located in southern Poland, which during World War II was under German occupation. The German forces killed 1.1 million people there. Most of the victims were Jewish, but others, including ethnic Poles, Soviet POWs and Roma, also lost their lives in large numbers there.