The invention relates to a chronograph mechanism (1; 201), for a timepiece movement, including a counter for a unit of time comprising:a display wheel capable of being rotated from a zero position,a return wheel, rotatable between an initial position, associated with the zero position of the display wheel, and a final position, the display wheel and the return wheel being arranged such that the return wheel pivots from its initial position to its final position when the display wheel makes one revolution,a resilient return member (20) arranged to act on the return wheel and to tend to return it to its initial position, the display wheel including a toothing arranged in mesh with the return wheel and having a truncated portion intended to allow the display wheel and the return wheel to be uncoupled on each complete revolution of the display wheel.