diff --git a/Shorewall/Perl/Shorewall/Chains.pm b/Shorewall/Perl/Shorewall/Chains.pm
index 7fc6bf0..e89b9f9 100644
--- a/Shorewall/Perl/Shorewall/Chains.pm
+++ b/Shorewall/Perl/Shorewall/Chains.pm
@@ -2223,7 +2223,7 @@ sub do_proto( $$$;$ )
 
 	if ( defined $protonum ) {
 	    #
-	    # Protocol is numeric and <= 65535 or is defined in /etc/protocols or NSS equivalent
+	    # Protocol is numeric and <= 255 or is defined in /etc/protocols or NSS equivalent
 	    #
 	    fatal_error "'!0' not allowed in the PROTO column" if $invert && ! $protonum;
 
diff --git a/Shorewall/Perl/Shorewall/IPAddrs.pm b/Shorewall/Perl/Shorewall/IPAddrs.pm
index 57d0988..b1fbc2d 100644
--- a/Shorewall/Perl/Shorewall/IPAddrs.pm
+++ b/Shorewall/Perl/Shorewall/IPAddrs.pm
@@ -330,7 +330,7 @@ sub resolve_proto( $ ) {
 
     if ( $proto =~ /^\d+$/ || $proto =~ /^0x/ ) {
 	$number = numeric_value ( $proto );
-	defined $number && $number <= 65535 ? $number : undef;
+	defined $number && $number <= 255 ? $number : undef;
     } else {
 	#
 	# Allow 'icmp' as a synonym for 'ipv6-icmp' in IPv6 compilations