A locking device locks a landing gear mounted in rotation on an aircraft and includes a deployment hydraulic jack including a first chamber connected to a first hydraulic supply and a second chamber connected to a second hydraulic supply. The locking device includes a hydraulic actuator connected to a rotary distributor. The rotary distributor includes a coupling operationally connecting the rotary distributor to a strut of the landing gear, a first supply port fluidly connected to the first hydraulic supply, and a first outlet port fluidly connected to the hydraulic actuator.