diff --git a/docs/extension_protocol.html b/docs/extension_protocol.html
index 1de9cf9f3..3ead11ba8 100644
--- a/docs/extension_protocol.html
+++ b/docs/extension_protocol.html
@@ -144,6 +144,16 @@ receiver's external ip address (no port is included).
This may be either an IPv4 (4 bytes) or an IPv6
(16 bytes) address.
+| ipv6 |
+If this peer has an IPv6 interface, this is the compact
+representation of that address (16 bytes). The client may
+prefer to connect back via the IPv6 address. |
+
+| ipv4 |
+If this peer has an IPv4 interface, this is the compact
+representation of that address (4 bytes). The client may
+prefer to connect back via this interface. |
+
| reqq |
An integer, the number of outstanding request messages
this client supports without dropping any. The default in
diff --git a/docs/extension_protocol.rst b/docs/extension_protocol.rst
index a097e4aec..742944a0b 100644
--- a/docs/extension_protocol.rst
+++ b/docs/extension_protocol.rst
@@ -93,6 +93,14 @@ Here are some other items that an implementation may choose to support:
| | This may be either an IPv4 (4 bytes) or an IPv6 |
| | (16 bytes) address. |
+--------+-----------------------------------------------------------+
+| ipv6 | If this peer has an IPv6 interface, this is the compact |
+| | representation of that address (16 bytes). The client may |
+| | prefer to connect back via the IPv6 address. |
++--------+-----------------------------------------------------------+
+| ipv4 | If this peer has an IPv4 interface, this is the compact |
+| | representation of that address (4 bytes). The client may |
+| | prefer to connect back via this interface. |
++--------+-----------------------------------------------------------+
| reqq | An integer, the number of outstanding request messages |
| | this client supports without dropping any. The default in |
| | in libtorrent is 250. |
|