diff --git a/base9/Settings.cpp b/base9/Settings.cpp
index d75bdf6..ed51d39 100644
--- a/base9/Settings.cpp
+++ b/base9/Settings.cpp
@@ -231,6 +231,7 @@ void Settings::fromCLI (int argc, char **argv)
         {"startingAv", required_argument, 0, 0xC6},
         {"startingY", required_argument, 0, 0xC5},
         {"startinglogAge", required_argument, 0, 0xC4},
+        {"startingCarbonicity", required_argument, 0, 0xC3},
         {0, 0, 0, 0}
     };
 
@@ -452,6 +453,10 @@ void Settings::fromCLI (int argc, char **argv)
                 istringstream (string (optarg)) >> cluster.starting.logAge;
                 break;
 
+            case 0xC3:
+                istringstream (string (optarg)) >> cluster.starting.carbonicity;
+                break;
+
             case '?':
                 // getopt_long already printed an error message.
                 printUsage ();