diff --git a/Shorewall/Perl/Shorewall/Config.pm b/Shorewall/Perl/Shorewall/Config.pm
index 2adfc6749..c0ab84ab6 100644
--- a/Shorewall/Perl/Shorewall/Config.pm
+++ b/Shorewall/Perl/Shorewall/Config.pm
@@ -5021,6 +5021,10 @@ sub read_capabilities() {
 	$capabilities{KERNELVERSION} = 20630;
     }
 
+    if ( ( $capabilities{CAPVERSION} || 0 ) < 40609 ) {
+	$capabilities{TCPMSS_TARGET} = 1
+    }
+
     $helpers_aliases{ftp}  = 'ftp-0',  $capabilities{FTP_HELPER}  = 1 if $capabilities{FTP0_HELPER};
     $helpers_aliases{irc}  = 'irc-0',  $capabilities{IRC_HELPER}  = 1 if $capabilities{IRC0_HELPER};
     $helpers_aliases{sane} = 'sane-0', $capabilities{SANE_HELPER} = 1 if $capabilities{SANE0_HELPER};