diff --git a/src/sshnames.rs b/src/sshnames.rs
index 9b5bb6d40980c665feae8fbb5c0e41d050ac70f2..dbb64c482e3157a156eb76b95fdbfc9db3e293c9 100644
--- a/src/sshnames.rs
+++ b/src/sshnames.rs
@@ -42,6 +42,9 @@ pub const SSH_NAME_NONE: &str = "none";
 /// [RFC4252](https://tools.ietf.org/html/rfc4252)
 pub const SSH_SERVICE_USERAUTH: &str = "ssh-userauth";
 /// [RFC4254](https://tools.ietf.org/html/rfc4254)
+///
+/// `IUTF8` is specified in
+/// [RFC8160](https://tools.ietf.org/html/rfc8160)
 pub const SSH_SERVICE_CONNECTION: &str = "ssh-connection";
 
 /// [RFC4252](https://tools.ietf.org/html/rfc4252)
diff --git a/src/termmodes.rs b/src/termmodes.rs
index 129a3e703b46f752d1283b37ba8ccddb31e1e023..f21d581889e9f8fbd663a34c8bd09d274b8896c4 100644
--- a/src/termmodes.rs
+++ b/src/termmodes.rs
@@ -1,5 +1,7 @@
 // TODO
-pub const NUM_MODES: usize = 56;
+pub const NUM_MODES: usize = 57;
+
+// Codes from rfc4254. IUTF8 from rfc8160
 /*
           0     TTY_OP_END  Indicates end of options.
           1     VINTR       Interrupt character; 255 if none.  Similarly
@@ -32,6 +34,7 @@ pub const NUM_MODES: usize = 56;
           39    IXANY       Any char will restart after stop.
           40    IXOFF       Enable input flow control.
           41    IMAXBEL     Ring bell on input queue full.
+          42    IUTF8       Terminal input and output is assumed to be encoded in UTF-8.
           50    ISIG        Enable signals INTR, QUIT, [D]SUSP.
           51    ICANON      Canonicalize input lines.
           52    XCASE       Enable input and output of uppercase