Recently, the German Federal Supreme Court (BGH) had to decide on the request of a complainant, himself sued for patent infringement, to become a party in an ex parte reinstatement procedure concerning the allegedly infringed patent. After the European patent was maintained in opposition in amended form, the patentee failed to perform the required validation steps in time before the German Patent and Trademark Office (GPTO). Having been informed by the GPTO about the loss of his German patent, the patentee requested reinstatement and simultaneously performed the required validation actions.