An electrical connector (100) comprises a first insulative housing (10) comprising a base section (110) extending along a first direction and defining a front end and a rear end thereof in a second direction vertical to the first direction. A mating section (120) extends forward from the front end of the base section in the second direction and a mating cavity (121) is defined in the mating section and opened forward. A receiving chamber (140) is provided in the rear end of the base section (110) and opened rearward. A plurality of terminal grooves (130) is arranged along the first direction and extends along the second direction. A second insulative housing (20) is received and retained in the receiving chamber (140) of the first insulative housing (10) with a plurality of passageways (210) corresponding with and aligning with said terminal grooves (130) in the second direction. A plurality of terminals (30) is retained in the terminal grooves and the passageways.