The invention relates to a plug-in connection, comprising a plug connector having a plug connector housing (1) and comprising a mating plug connector that can be plugged together with the plug connector, wherein the plug connector has a superstructure (4) and the superstructure (4) accommodates a locking element (8) in a preliminary latching position and a final latching position, wherein the plug connector has first latching means and the locking element (8) has first latching means corresponding thereto and the mating plug connector has further latching means and the locking element (8) has further latching means corresponding thereto, wherein the locking element (8) is first fastened to the plug connector in the preliminary latching position by means of the first latching means corresponding to each other before the mating plug connector is inserted into the plug connector, and the further latching means corresponding to each other are actuated by means of the insertion of the mating plug connector into the plug connector, whereby the locking element (8) can be moved into the final latching position thereof, characterized in that the plug connector housing (1) and the locking element (8) have third latching means corresponding to each other, by means of which additional locking of the locking element (8) to the plug connector occurs when the locking element has been moved into the final latching position thereof.