OTTAWA—A new rule requiring some Canadians with dual citizenship to use a Canadian passport to enter the country takes effect today.

The federal government announced the rule earlier this year — it doesn’t apply to those who have dual Canadian-American citizenship.

A new electronic system will scan passports at check in to verify that all passengers boarding flights have the appropriate documents to enter Canada.

The government was set to start enforcing the new rules at the end of September, but held off until today because some travellers complained that they didn’t get enough notice to get a Canadian passport.