A high-temperature patch plug (50) for one or more connection lines (60), especially for connecting electric supply and/or signal lines to heating elements and/or thermocouples or temperature sensors. The patch plug (50) has one or more poles each with a contact element (64) connected to an inner conductor (61) of a connection line (60), and with a one-piece, insulating housing (51), which surrounds an interior (59), in which at least the at least one contact element (64) is accommodated at least partially. The housing (51) has at least one insertion opening (63) on the side facing away from the plugging side and a passage opening (57), which is connected to the insertion opening via the interior (59) of housing (51) for each pole on the side facing the plugging side. The contact element (64) is locked in the housing (51) for each pole at a locking step (53) arranged in the interior of the housing such that a motion of the contact element (64) against the plugging direction is limited by the locking, wherein said locking step (53) is formed by an irreversible deformation of housing.