The city of Amsterdam, famed for its weed cafes and easygoing approach to the drug, plans to ban smoking marijuana at schools.
City spokeswoman Iris Reshef says the move is necessary because stoned students are a problem at some schools.
Schools had always forbidden the drug, but found it difficult to enforce the rule due to the country's tolerance policy.
Under tolerance, pot is technically illegal but police cannot prosecute people for possession of small amounts.
After a change in national law, the city can now ban the drug at schools under a public nuisance ordinance, and police can levy fines against pupils who break the rules.