diff -ru psmisc-22.21/src/fuser.c psmisc-22.21-modified/src/fuser.c --- psmisc-22.21/src/fuser.c 2014-01-31 05:07:32.000000000 -0800 +++ psmisc-22.21-modified/src/fuser.c 2016-03-11 17:43:56.981300845 -0800 @@ -1174,7 +1174,7 @@ usage(_("No process specification given")); /* Check if -M flag was used and if so check mounts */ - if (opts * OPT_ISMOUNTPOINT) { + if (opts & OPT_ISMOUNTPOINT) { check_mountpoints(&mounts, &names_head, &names_tail); }