An electrical connector includes: an insulative housing having a base and a tongue; an upper and lower rows of contacts secured to the housing and exposed respectively to an upper and lower surfaces of the tongue, each row of contacts including two outermost ground contacts; and a shielding shell enclosing the contact module; wherein at least one of the ground contacts in one or both rows of the contacts has an extension, and the tongue has on at least one of the upper and lower surfaces a step exposing the extension.