A timepiece including a case that accommodates a movement including a lower peripheral bearing surface, the case including a case middle to which a back cover and a crystal are respectively assembled. The timepiece further includes a clamping element including a lower retaining surface and the movement includes an upper peripheral bearing surface, the lower retaining surface of the clamping element and the upper peripheral bearing surface being in mutual contact. The back cover includes an annular peripheral shoulder, against which is affixed the lower peripheral bearing surface of the movement, which is compressed between its lower peripheral bearing surface and its upper peripheral bearing surface respectively by the annular peripheral shoulder of the back cover and the lower retaining surface of the clamping element.