Some kids in London, England are being discouraged from having a best friend at school.

Psychologist Gaynor Sbuttoni, a specialist in children’s behaviour, told a London newspaper that some elementary teachers aren’t letting students have a best friend. Instead, they are urging children to play together in groups.

The Sun newspaper reported that Russell Hobby, of the UK’s National Association of Head Teachers, said some schools there have best-friend bans.

Teachers say the reason they do this is so kids don’t get hurt if they split up with their friend.