The wear-compensation device for a gear comprises a fixed support capable of being fixed axially on an external element in order to keep the device on the said external element, a bearing designed to be mounted on a shaft comprising one of the wheels of the gear, an eccentric mounted on the bearing and designed to be in contact with the external element, the said eccentric being able to move angularly relative to the fixed support. The device also comprises a torsion spring mounted axially between the fixed support and the eccentric and capable of exerting a circumferential preload force on the said eccentric, the said spring comprising a first end mounted inside a recess of the eccentric and a second end interacting with the fixed support.