Disclosed is a timepiece assembly including at least two elements in contact and mobile relative to each other, one of the elements having at least a first contact surface intended to rub against at least a second contact surface of the other element under dry lubrication conditions. At least one of the first and second contact surfaces is covered with a hydrophobic coating having an angle of contact with water greater than 90, preferably greater than 100 and preferably greater than 110, and a coefficient of friction lower than 0.15, preferably lower than 0.12 and preferably lower than 0.1, the variation in the coefficient of friction as a function of the relative humidity being lower than 25%, preferably lower than 10% and preferably lower than 5%.