A guard for preventing the vandalism of the vault and vault door of a pay telephone, comprising a plurality of rigid segments. Each rigid segment includes an attachment end and a free end, defining a perpendicular distance therebetween. Each of the rigid segments is attached at its attachment end to the lower housing of the pay telephone immediately adjacent and substantially surrounding the vault door. In the preferred embodiment, the plurality of rigid segments comprise one integral rigid member. The guard changes the leverage point of the pry bar of a vandal so as to prohibit such vandal from forceably removing the vault door. The leverage point is changed from proximate the vault door to the free end of a rigid segment or integral rigid member.