--- iputils/doc/ping.8
+++ iputils/doc/ping.8
@@ -118,7 +118,7 @@
 when finished.
 .TP
 \fB-R\fR
-Record route.
+Record route. (IPv4 only)
 Includes the RECORD_ROUTE option in the ECHO_REQUEST
 packet and displays the route buffer on returned packets.
 Note that the IP header is only large enough for nine such routes.
--- iputils/doc/ping.sgml
+++ iputils/doc/ping.sgml
@@ -200,7 +200,7 @@
  <varlistentry>
   <term><option/-R/</term>
   <listitem><para>
-Record route.
+Record route. (IPv4 only)
 Includes the RECORD_ROUTE option in the ECHO_REQUEST
 packet and displays the route buffer on returned packets.
 Note that the IP header is only large enough for nine such routes.