All parliamentarians and ministers will have to reveal which passports they hold.
The new rule has been hailed by the Swiss People’s Party as a victory for transparency.
It won’t make much of a difference as there are no restrictions on dual nationals being elected or holding high office.
The issue came up after the current foreign minister Ignazio Cassis was appointed. He holds an Italian passport. Some questioned it may impact his commitment to Switzerland.
He offered to renounce his extra citizenship.
The new rules have now been agreed by both houses of parament. But the Green Party says it infringes on personal liberty.