Abstract: An extension is provided at each end of a glue flap of a conventional carton blank, the extensions being glued to conventional carton dust flaps to thereby provide improved tamper resistance to a sealed end carton when intrusion is attempted along glue seam for purposes of violating the contents, i.e. pharmaceutical products and the like, contained within primary packaging contained within the carton (secondary packaging). The extensions prevent withdrawal of the dust flaps to which the extensions are glued after the glue seam is penetrated. If the dust flaps are forcibly withdrawn, positive visual indication of tampering will result to thereby alert a potential consumer.