The invention relates to a plug connector, in particular a direct plug connector, for contacting contact openings of a circuit board, the plug connector including a contact carrier which can include coding devices, in particular coding pins and a polarity reversal safety, in particular configured as polarity protrusions; conductor insertion channels formed by the contact carrier and configured to receive connection conductors, and contact recesses configured to receive plug contacts; a primary safety that supports the contact carrier at the circuit board and that is in particular configured as interlocking elements, characterized in that, the contact carrier is provided with a secondary safety which fixes the contact carrier at the circuit board in addition to the primary safety and which is operable independently from the primary safety.