diff --git a/include/netinet/ip6.h b/include/netinet/ip6.h
index b7a4799508..4a94b51556 100644
--- a/include/netinet/ip6.h
+++ b/include/netinet/ip6.h
@@ -32,6 +32,32 @@
  * Public Type Definitions
  ****************************************************************************/
 
+struct ip6_hdr
+{
+  union
+  {
+    struct ip6_hdrctl
+    {
+      uint32_t ip6_un1_flow;   /* 4 bits version, 8 bits TC, 20 bits flow-ID */
+      uint16_t ip6_un1_plen;   /* payload length */
+      uint8_t  ip6_un1_nxt;    /* next header */
+      uint8_t  ip6_un1_hlim;   /* hop limit */
+    } ip6_un1;
+
+    uint8_t ip6_un2_vfc;       /* 4 bits version, top 4 bits tclass */
+  } ip6_ctlun;
+
+  struct in6_addr ip6_src;      /* source address */
+  struct in6_addr ip6_dst;      /* destination address */
+};
+
+#define ip6_vfc   ip6_ctlun.ip6_un2_vfc
+#define ip6_flow  ip6_ctlun.ip6_un1.ip6_un1_flow
+#define ip6_plen  ip6_ctlun.ip6_un1.ip6_un1_plen
+#define ip6_nxt   ip6_ctlun.ip6_un1.ip6_un1_nxt
+#define ip6_hlim  ip6_ctlun.ip6_un1.ip6_un1_hlim
+#define ip6_hops  ip6_ctlun.ip6_un1.ip6_un1_hlim
+
 /****************************************************************************
  * Public Function Prototypes
  ****************************************************************************/