--- a/net.c
+++ b/net.c
@@ -307,9 +307,11 @@ void net_send_tcp(int index)
   struct sockaddr_storage local;
   struct sockaddr_storage remote;
   struct sockaddr_in *local4 = (struct sockaddr_in *) &local;
-  struct sockaddr_in6 *local6 = (struct sockaddr_in6 *) &local;
   struct sockaddr_in *remote4 = (struct sockaddr_in *) &remote;
+#ifdef ENABLE_IPV6
+  struct sockaddr_in6 *local6 = (struct sockaddr_in6 *) &local;
   struct sockaddr_in6 *remote6 = (struct sockaddr_in6 *) &remote;
+#endif
   socklen_t len;
 
   ttl = index + 1;
@@ -566,8 +568,10 @@ void net_send_query(int index)
 
   /* sendto() assumes packet length includes the IPv4 header but not the 
      IPv6 header. */
-  spacketsize = abs(packetsize)	-
-		( ( af == AF_INET ) ? 0 : sizeof (struct ip6_hdr) );
+  spacketsize = abs(packetsize);
+#ifdef ENABLE_IPV6
+  spacketsize -= ( ( af == AF_INET ) ? 0 : sizeof (struct ip6_hdr) );
+#endif
   rv = sendto(sendsock, packet, spacketsize, 0, remotesockaddr, salen);
   if (first && (rv < 0) && ((errno == EINVAL) || (errno == EMSGSIZE))) {
     /* Try the first packet again using host byte order. */
--- a/dns.c
+++ b/dns.c
@@ -49,7 +49,7 @@
 #include <unistd.h>
 #include <fcntl.h>
 //#include <ctype.h>
-//#include <string.h>
+#include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <signal.h>
--- a/net.h
+++ b/net.h
@@ -20,6 +20,7 @@
 #include <netdb.h>
 #include <arpa/inet.h>
 #include <netinet/in.h>
+#include <sys/select.h>
 #include <sys/socket.h>
 #ifdef ENABLE_IPV6
 #include <netinet/ip6.h>