An electrical connector (100) includes an insulative housing (1) comprising an engaging portion (12) which comprises a pair of side walls (121) and a pair of end walls (122), a plurality of signal terminals (2) arranged along the pair of the side walls (121) and at least one power terminals (3) located at each end wall (122). The end wall (122) defines at least one groove (120) extending along a mating direction at an outside thereof to receive and retain the at least one power terminal (3).