diff --git a/ipv6.ino b/ipv6.ino
index 96ea3ac..0bfc1bb 100644
--- a/ipv6.ino
+++ b/ipv6.ino
@@ -82,13 +82,11 @@ void IPv6Packet::setDstAddress(IPv6Addr& address) {
 void IPv6Packet::setPayload(char* payload, int len) {
     memset(packet, 0, LEN);
     
-    ipv6_packet_header* header = (ipv6_packet_header*)packet;
-    memcpy(header->field, "\x60\x00\x00\x00", 4);
-    
-    memcpy(header->len + 1, (char*)&len, 1);
-    header->hop_limit = 64;
+    *(packet) = 0x60;               /* IP version 6 */
+    *(packet + 4 + 1) = len & 0xff; /* length */
+    *(packet + 7) = 64;             /* hop limit / ttl */
 
-    memcpy(packet + sizeof(ipv6_packet_header), payload, len);
+    memcpy(packet + 40, payload, len);  /* actual payload */
   }
 
  void IPv6Packet::doAction() {