diff --git a/cli-runopts.c b/cli-runopts.c
index 07fce1b..38a73f7 100644
--- a/cli-runopts.c
+++ b/cli-runopts.c
@@ -83,6 +83,7 @@ static void printhelp() {
 					"-W <receive_window_buffer> (default %d, larger may be faster, max 10MB)\n"
 					"-K <keepalive>  (0 is never, default %d)\n"
 					"-I <idle_timeout>  (0 is never, default %d)\n"
+					"-z    disable QoS\n"
 #if DROPBEAR_CLI_NETCAT
 					"-B <endhost:endport> Netcat-alike forwarding\n"
 #endif				
@@ -98,7 +99,6 @@ static void printhelp() {
 #if DEBUG_TRACE
 					"-v    verbose (repeat for more verbose)\n"
 #endif
-					"-z    disable IP Type-Of-Service feature\n"
 					,DROPBEAR_VERSION, cli_opts.progname,
 #if DROPBEAR_CLI_PUBKEY_AUTH
 					DROPBEAR_DEFAULT_CLI_AUTHKEY,
diff --git a/dbclient.1 b/dbclient.1
index e55b45c..fbbbc1b 100644
--- a/dbclient.1
+++ b/dbclient.1
@@ -111,6 +111,9 @@ if 0 disables keepalives. If no response is received for 3 consecutive keepalive
 .B \-I \fIidle_timeout
 Disconnect the session if no traffic is transmitted or received for \fIidle_timeout\fR seconds.
 .TP
+.B \-z
+By default Dropbear will send network traffic with the \fBAF21\fR setting for QoS, letting network devices give it higher priority. Some devices may have problems with that, \fI-z\fR can be used to disable it.
+.TP
 
 .\" TODO: how to avoid a line break between these two -J arguments?
 .B \-J \fIproxy_command
diff --git a/dropbear.8 b/dropbear.8
index 298c220..d9bbfc2 100644
--- a/dropbear.8
+++ b/dropbear.8
@@ -101,6 +101,9 @@ of 0 disables keepalives. If no response is received for 3 consecutive keepalive
 .B \-I \fIidle_timeout
 Disconnect the session if no traffic is transmitted or received for \fIidle_timeout\fR seconds.
 .TP
+.B \-z
+By default Dropbear will send network traffic with the \fBAF21\fR setting for QoS, letting network devices give it higher priority. Some devices may have problems with that, \fI-z\fR can be used to disable it.
+.TP
 .B \-T \fImax_authentication_attempts
 Set the number of authentication attempts allowed per connection. If unspecified the default is 10 (MAX_AUTH_TRIES)
 .TP
diff --git a/svr-runopts.c b/svr-runopts.c
index aae4ca1..cb92595 100644
--- a/svr-runopts.c
+++ b/svr-runopts.c
@@ -104,6 +104,7 @@ static void printhelp(const char * progname) {
 					"-W <receive_window_buffer> (default %d, larger may be faster, max 10MB)\n"
 					"-K <keepalive>  (0 is never, default %d, in seconds)\n"
 					"-I <idle_timeout>  (0 is never, default %d, in seconds)\n"
+					"-z    disable QoS\n"
 #if DROPBEAR_PLUGIN
                                         "-A <authplugin>[,<options>]\n"
                                         "               Enable external public key auth through <authplugin>\n"
@@ -112,7 +113,6 @@ static void printhelp(const char * progname) {
 #if DEBUG_TRACE
 					"-v    verbose (repeat for more verbose)\n"
 #endif
-					"-z		disable IP Type-Of-Service feature\n"
 					,DROPBEAR_VERSION, progname,
 #if DROPBEAR_DSS
 					DSS_PRIV_FILENAME,