diff --git a/libc/Android.bp b/libc/Android.bp
index 51db9b7..2b1c7ca 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -1698,6 +1698,7 @@
         symbol_file: "libc.map.txt",
         versions: [
             "29",
+            "R",
             "10000",
         ],
     },
diff --git a/libc/include/netinet/icmp6.h b/libc/include/netinet/icmp6.h
index 43ec521..2b237a8 100644
--- a/libc/include/netinet/icmp6.h
+++ b/libc/include/netinet/icmp6.h
@@ -280,6 +280,8 @@
 #define ND_OPT_ROUTE_INFO		24	/* RFC 4191 */
 #define ND_OPT_RDNSS			25	/* RFC 6016 */
 #define ND_OPT_DNSSL			31	/* RFC 6016 */
+#define ND_OPT_CAPTIVE_PORTAL		37	/* RFC 7710 */
+#define ND_OPT_PREF64			38	/* RFC-ietf-6man-ra-pref64-09 */
 
 struct nd_opt_route_info {	/* route info */
 	u_int8_t	nd_opt_rti_type;
@@ -335,6 +337,19 @@
 	/* followed by list of IP prefixes */
 } __packed;
 
+struct nd_opt_captive_portal {	/* CAPTIVE PORTAL option RFC 7710 */
+	u_int8_t	nd_opt_captive_portal_type;   // ND_OPT_CAPTIVE_PORTAL
+	u_int8_t	nd_opt_captive_portal_len;    // in 8 byte units
+	u_int8_t	nd_opt_captive_portal_uri[];  // 6 + n*8 bytes
+} __packed;
+
+struct nd_opt_pref64 {		/* PREF64 option RFC-ietf-6man-ra-pref64-09 */
+	u_int8_t	nd_opt_pref64_type;          // ND_OPT_PREF64
+	u_int8_t	nd_opt_pref64_len;           // 8 byte units, thus '2'
+	u_int16_t	nd_opt_pref64_lifetime_plc;  // net endian, 13 + 3 bits
+	u_int8_t	nd_opt_pref64_prefix[12];    // top 96 bits
+} __packed;
+
 /*
  * icmp6 namelookup
  */