A plug connector (11, 12), having a body (13, 16) with boreholes containing contacts (14, 15), and a detent (23-26) that protrudes into the boreholes (21, 22) behind a contact collar (65). To make possible the locking insertion of not only thicker and therefore relatively stiff cables but also of such thin cables, for example those that are braided, which due to their relatively small cross section easily buckle when stressed in the sliding longitudinal direction, it is provided that the detent (23-26) can be inserted into the borehole (21, 22) in two successive positions, whereby in the first, preliminary locking position, the deflection resistance of the detent (23, 26) is smaller than it is when bringing the plug contact (14, 13) into the second, and final locking position.