A device for detecting breakage of a turbomachine shaft is disclosed. The device includes a shaft having an upstream end and a downstream end; a rod having an upstream end and a downstream end, and placed coaxially inside the shaft, the downstream end of the rod being securely fastened to the downstream end of the shaft and the upstream end of the rod being free to rotate relative to the upstream and of the shaft; and a sensor suitable for detecting a difference in speed of rotation between the upstream end of the rod and the upstream end of the shaft.