An electrical connector includes a housing, signal contacts and ground contacts, and a ground bus bar. The housing has a first side wall and a second side wall that define a socket at the front end of the housing. The socket is configured to receive a mating connector therein. The signal and ground contacts are held in the housing and interspersed along at least one of the first or second side wall. The signal and ground contacts extend into the socket to mate with corresponding mating signal contacts and mating ground contacts, respectively, of the mating connector. The ground bus bar is coupled to the housing at the first side wall of the socket. The ground bus bar includes spring contacts that extend into the socket and are configured to engage corresponding mating ground contacts of the mating connector to electrically common the mating ground contacts.