Abstract: A holder for the mold halves of an IS machine for making hollow glass articles and parison or finished molds thereof, has an addition to the rockers allowing X-axis compensation for irregularities in the mold halves, a compensating device which affords compensation for irregularities with respect to a Y-axis and thus permits adjustment of the ends of the mold halves with respect to one another. The compensating device utilizes a vertical pin from which an arm projects to pivotally carry a vertical compensating lever whose upper and lower ends are pivotally connected to cover plates which, in turn, are connected to the respective mold half.