diff --git a/examples/ipv6/rpl-udp/udp-client.c b/examples/ipv6/rpl-udp/udp-client.c
index c7c425c7b..e5b27f832 100644
--- a/examples/ipv6/rpl-udp/udp-client.c
+++ b/examples/ipv6/rpl-udp/udp-client.c
@@ -78,7 +78,7 @@ send_packet(void *ptr)
 
   seq_id++;
   PRINTF("DATA send to %d 'Hello %d'\n",
-         client_conn->ripaddr.u8[15], seq_id);
+         server_ipaddr.u8[sizeof(server_ipaddr.u8) - 1], seq_id);
   sprintf(buf, "Hello %d from the client", seq_id);
   uip_udp_packet_sendto(client_conn, buf, strlen(buf),
                         &server_ipaddr, UIP_HTONS(UDP_SERVER_PORT));
diff --git a/examples/ipv6/rpl-udp/udp-server.c b/examples/ipv6/rpl-udp/udp-server.c
index 0a5f83e93..2ce2a046d 100644
--- a/examples/ipv6/rpl-udp/udp-server.c
+++ b/examples/ipv6/rpl-udp/udp-server.c
@@ -64,7 +64,8 @@ tcpip_handler(void)
     appdata = (char *)uip_appdata;
     appdata[uip_datalen()] = 0;
     PRINTF("DATA recv '%s' from ", appdata);
-    PRINTF("%d", UIP_IP_BUF->srcipaddr.u8[15]);
+    PRINTF("%d",
+           UIP_IP_BUF->srcipaddr.u8[sizeof(UIP_IP_BUF->srcipaddr.u8) - 1]);
     PRINTF("\n");
 #if SERVER_REPLY
     uip_ipaddr_copy(&server_conn->ripaddr, &UIP_IP_BUF->srcipaddr);