An electrical connector assembly is provided for mounting on a circuit board. The assembly includes a first connector having a first dielectric housing fixed to the circuit board. A plurality of conductive terminals are mounted on the housing and are electrically connected to appropriate circuit traces on the circuit board. A second connector includes a second dielectric housing mateable with the first dielectric housing. A plurality of conductive terminals are mounted on the second housing for engaging the terminals of the first connector when the connectors are mated. At least one locking member is provided on the second dielectric housing and is lockable with the circuit board when the connectors are mated. Therefore, extraneous forces applied to the second connector are passed directly to the circuit board to protect the first connector and its connections to the board.