diff -ru ucarp-1.5.2.orig/src/ucarp_p.h ucarp-1.5.2/src/ucarp_p.h
--- ucarp-1.5.2.orig/src/ucarp_p.h	2009-05-27 21:39:23.000000000 +0000
+++ ucarp-1.5.2/src/ucarp_p.h	2020-02-09 17:57:05.816000000 +0000
@@ -1,7 +1,7 @@
 #ifndef __CARP_P_H__
 #define __CARP_P_H__ 1
 
-static const char *GETOPT_OPTIONS = "i:s:v:p:Pa:hb:k:x:nu:d:r:zf:BoSM";
+static const char *GETOPT_OPTIONS = "i:s:v:p:Pa:hb:k:x:nu:d:r:zf:Bo:SM";
 
 static struct option long_options[] = {
     { "interface", 1, NULL, 'i' },