diff --git a/src/configure.in b/src/configure.in
index c7f049749ee47505f3472c068826bb16f7b7148c..091346153e42a277d2cd20bd34dcba2c25303a08 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -238,11 +238,11 @@ AC_ARG_WITH(mb,
     [  --with-mb=<encoding>    enable multi-byte support ], 
     [
 	case "$withval" in
-	EUC_JP|EHC_CN|EUC_KR|EUC_TW|UNICODE|MULE_INTERNAL|LATIN1|LATIN2|LATIN3|LATIN4|LATIN5)
+	EUC_JP|EHC_CN|EUC_KR|EUC_TW|UNICODE|MULE_INTERNAL|LATIN1|LATIN2|LATIN3|LATIN4|LATIN5|KOI8|WIN|ALT)
 	    AC_MSG_RESULT("enabled with $withval")
             ;;
 	*)
-	    AC_MSG_ERROR([*** You must supply an argument to the --with-mb option one of EUC_JP,EHC_CN,EUC_KR,EUC_TW,UNICODE,MULE_INTERNAL,LATIN1-5])
+	    AC_MSG_ERROR([*** You must supply an argument to the --with-mb option one of EUC_JP,EHC_CN,EUC_KR,EUC_TW,UNICODE,MULE_INTERNAL,LATIN1-5,KOI8,WIN,ALT])
 	  ;;
 	esac
 	MULTIBYTE="$withval"