This invention relates to 2-Aza-bicyclo[2.2.1]heptane-3-carboxylic acid (benzyl-cyano-methyl)-amides of formula 1 and their use as inhibitors of Cathepsin C, pharmaceutical compositions containing the same, and methods of using the same as agents for treatment and/or prevention of diseases connected with dipeptidyl peptidase I activity, e.g. respiratory diseases.