A striker plate has an exterior edge, an interior edge, and a latch-receiving hole. The latch-receiving width is defined by inner and outer sides of the latch-receiving hole. A supplemental hole formed in the striker plate constitutes an inwardly extending extension of the latch-receiving hole. An adjustment block is coupled to the striker plate adjacent to the supplemental hole. The threaded end of a threaded adjustment bolt is received in a threaded aperture of the adjustment block. The threaded adjustment bolt has a head in the supplemental hole accessible to a user for rotation and axial movement to and from the latch-receiving hole to effectively vary the width of the latch-receiving hole.