I<Type of Service> (ToS) aliases were used to specify the bits of outgoing
 packets.
 
+=item B<-Z> I<percent>
+
+If any hosts have a drop rate higher than I<percent>, where I<percent> is a
+number between zero and 100 inclusively, exit with a non-zero exit status.
+Since it is not possible to have a higher drop rate than 100%, passing this
+limit will effectively disable the feature (the default). Setting the option to
+zero means that the exit status will only be zero if I<all> replies for I<all>
+hosts have been received.
+
 =back
 
 =head1 COLORS
 
 static int     opt_count      = -1;
 static int     opt_send_ttl   = 64;
 static uint8_t opt_send_qos   = 0;
+static double  opt_exit_status_threshold = 1.0;
 
 static int host_num = 0;
 
                        "  -I srcaddr   source address\n"
                        "  -D device    outgoing interface name\n"
                        "  -f filename  filename to read hosts from\n"
+                       "  -Z percent   Exit with non-zero exit status if more than this percentage of\n"
+                       "               probes timed out. (default: never)\n"
 
                        "\noping "PACKAGE_VERSION", http://verplant.org/liboping/\n"
                        "by Florian octo Forster <octo@verplant.org>\n"
 
        while (1)
        {
-               optchar = getopt (argc, argv, "46c:hi:I:t:Q:f:D:");
+               optchar = getopt (argc, argv, "46c:hi:I:t:Q:f:D:Z:");
 
                if (optchar == -1)
                        break;
                                set_opt_send_qos (optarg);
                                break;
 
+                        case 'Z':
+                       {
+                               char *endptr = NULL;
+                               double tmp;
+
+                               errno = 0;
+                               tmp = strtod (optarg, &endptr);
+                               if ((errno != 0) || (endptr == NULL) || (*endptr != 0))
+                                       fprintf (stderr, "The \"-Z\" option requires a numeric argument.\n");
+                               else if ((tmp >= 0.0) && (tmp <= 100.0))
+                                       opt_exit_status_threshold = tmp / 100.0;
+                               else
+                                       fprintf (stderr, "The argument of the \"-Z\" option must be between 0 and 100.\n");
+
+                               break;
+                       }
+
                        case 'h':
                                usage_exit (argv[0], 0);
                                break;
                                context->latency_total);
 
                {
-                 /* threshold for counting failed returns is 50%, rounding up */
-                 int threshold = (context->req_sent + 1) / 2;
-                 if (context->req_rcvd < threshold)
-                   failure_count += threshold - context->req_rcvd;
+                       double pct_failed = 1.0 - (((double) context->req_rcvd)
+                                       / ((double) context->req_sent));
+                       if (pct_failed > opt_exit_status_threshold)
+                               failure_count++;
                }
 
                if (context->req_rcvd != 0)