Lawmakers in Benin approved on Saturday a constitutional amendment extending the presidential term of office from five years to seven and creating an upper house of parliament.
The limit on the number of presidential terms remains set at two in the west African nation.
Current head of state Patrice Talon will step down next April after a decade in power.
His candidate, Finance Minister Romuald Wadagni, is the clear favourite to win the April presidential election.
The amendment was adopted by a large majority of MPs, with 90 votes in favour and 19 against.
The senate will be composed of at least 25 parliamentarians, some appointed by the head of state and other ex-officio members, such as former presidents.
