return nr;
 }
 
+static const char write_tree_usage[] = "git-write-tree [--missing-ok]";
+
 int main(int argc, char **argv)
 {
        int i, funny;
                if (!strcmp(argv[1], "--missing-ok"))
                        missing_ok = 1;
                else
-                       die("unknown option %s", argv[1]);
+                       die(write_tree_usage);
        }
        
        if (argc > 2)