Abstract: A paperboard insert for cigarette cartons is provided to restrict the lateral movement of smaller size cigarette packages contained in a standard size cigarette carton to enable the packages to be reliably stamped by standard tax marking machinery. The insert blank has a bottom, sides for abutting cigarette packages, spacers to position the insert sides inwardly of the carton walls and generally centered along the longitudinal axis of the carton, and attachment tabs to connect the insert to the carton walls. The insert blank may be attached to a standard carton blank prior to erection of the carton, allowing the insert to be erected simultaneously with the carton as a consequence of ordinary carton erection procedures.