Article 69 of the Belgian Constitution sets forth four qualifications for senators: each senator must be at least 18 years old, must possess the Belgian nationality, must have the full enjoyment of civil and political rights, and must be resident in Belgium. Originally, the minimum age to be elected senator was 40; this was reduced to 21 in 1993 and eventually to 18 in 2014. A senator can only enter into office after having taken the constitutional oath, in either of the three official languages in Belgium: Dutch, French or German. They may also choose to take the oath in more than one language. The oath is as follows: ""I swear to observe the Constitution"". (, , )