A tamper resistant assembly provides tamper resistance to an electrical receptacle. The tamper resistant assembly includes a base member having first and second grooves. Each groove has a first portion and a second portion connected to the first portion. The first portion is substantially perpendicular to a rear wall of the member and the second portion forms an angle with the first portion. A shutter member is slidably and pivotally connected to the base member for movement between open and closed positions. First and second protrusions extend outwardly from the shutter member and are slidably and pivotally received in the first and second grooves, respectively, in the base member. The first and second protrusions are disposed in the first portions of the grooves when the shutter member is in the closed position and prevent lateral sliding movement of the shutter member to prevent insertion of a foreign object past the shutter member, and in the second portions when the shutter member is in the open position by allowing lateral sliding of the shutter member. The first portions prevent lateral movement of the shutter member and allow pivoting movement of the shutter member to positions preventing insertion of a foreign object past the shutter member.