An electrical connector assembly includes an electrical connector and a complementary connector mated with the electrical connector. The electrical connector includes a shell and a terminal module received in the shell. The shell defining a mating portion extending forwardly and a receiving room recessed from the rear face thereof. The mating portion defines a mating face at a side surface thereof. The terminal module includes an insulator and a plurality of first terminals retained in the insulator. The insulator defines a first face and a second face opposite to the first face. The first terminals includes contacting portions protruding from the first face of the insulator. A supporting plate is inserted between the second face of the insulator and an inner surface of the receiving room and pushing the contacting portions of the first terminals exposed to the mating face.