Pope Francis drew appreciative laughter Sunday when he addressed cloistered nuns in a Peruvian church, Reuters reported. The nuns were given special permission to leave their convents to see the pontiff speak in Lima.

Francis spoke to the 500 nuns, known as “contemplatives” because they rarely venture away from their convents, on his final day in Peru.

“Seeing you all here an unkind thought comes to my mind, that you took advantage (of me) to get out of the convent a bit to take a stroll,” he said at the Cathedral San Juan Apostol y Evangelista in Lima, drawing roars of laughter from the nuns, Reuters reported.

Francis also urged the nuns to avoid gossiping in their convents, likening it to “terrorism.”

“You know what a gossiping nun is?” he asked. “A terrorist.”

The nuns laughed again, Reuters reported.

“Because gossip is like a bomb. One throws it, it causes destruction and you walk away tranquilly.” Francis said. “No terrorist nuns! No gossip, and know that the best remedy against gossip is to bite your tongue.”