From http://people.freebsd.org/~kib/misc/amtterm.1.patch

--- redir.c	2011-05-26 12:19:45.000000000 +0300
+++ redir.c	2011-12-28 22:39:15.164012594 +0200
@@ -18,6 +18,10 @@
  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
--- tcp.c	2011-05-26 12:19:45.000000000 +0300
+++ tcp.c	2011-12-28 22:39:32.276853072 +0200
@@ -18,6 +18,10 @@
  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <errno.h>