Soccer rivalries can range from sibling teasing to full-on war, with the most hated of rivals openly launching attacks–verbal and otherwise–at each other. With that in mind, a teacher who is a self-proclaimed River Plate diehard decided to put aside club-related differences in the aftermath of Boca Juniors’ historic 32nd Primer Division title.

Alberto González, who is a teacher at the Escuela Adventista de Neuquén and a diehard River Plate hincha, greeted his students that root for River’s hated cross-town rivals, Boca Juniors, with a celebratory sticker–placed in the notebooks of the students he knew to be fans of the champs–congratulating them on their team’s accomplishment:

The sticker, which quickly went viral in Argentina, reads: “I know how beautiful it is for a devoted fan to see their team as champion, and I’m happy to see you happy. Congratulations, champion! Let’s never let a jersey convert us into enemies. With love, your professor Toto, a River Plate hincha.”

Apparently, the reaction from González’s students was so positive that other students outside of the class went up to him, asking for stickers in their notebooks. Parents also wrote in to thank the teacher, who believes this was so successful because his students know he is a die-hard River fan; to cross the line of rivalry was seen as a huge deal.

Speaking to LM Neuquén, González said that “The idea is to promote non-violence, because in soccer, there can be a lot of violence, and there’s no limit to what we do to each other.” He went on to say that “we are so used to living in a violent society, which is why something like this stands out. Soccer should be enjoyed.”