Disclosed is a locking device for a buckle. The device comprises a housing, a lever and an arm. The lever has a first strap engaging end and a locking portion. The lever is connected to the housing for movement relative to the housing. The locking portion is cooperable with the housing to be retained in it. The housing is configured to receive a strap. The arm is resiliently connected to the housing and has a second strap engaging end and a lifting end portion. The lifting end portion is disposed towards the first strap engaging end, such that in a locked position, when the locking portion cooperates with the housing, the second strap engaging end is urged into engagement with the strap. The lifting end portion contacts the first strap engaging end to lift it away from the strap.