- setsockopt($sock, IPPROTO_TCP, Socket::TCP_DEFER_ACCEPT(), 5) or die;
- my $x = getsockopt($sock, IPPROTO_TCP, Socket::TCP_DEFER_ACCEPT());
+ $TCP_DEFER_ACCEPT = eval { Socket::TCP_DEFER_ACCEPT() } // 9;
+ setsockopt($sock, IPPROTO_TCP, $TCP_DEFER_ACCEPT, 5) or die;
+ my $x = getsockopt($sock, IPPROTO_TCP, $TCP_DEFER_ACCEPT);