diff --git a/man7/ipv6.7 b/man7/ipv6.7
index c4e6cac30..16c760bc3 100644
--- a/man7/ipv6.7
+++ b/man7/ipv6.7
@@ -393,6 +393,18 @@ Programs that assume that all address types can be stored safely in a
 need to be changed to use
 .I struct sockaddr_storage
 for that instead.
+.PP
+.BR SOL_IP ,
+.BR SOL_IPV6 ,
+.B SOL_ICMPV6
+and other
+.BR SOL_ *
+socket options are not portable
+variants of
+.BR IPPROTO_ *.
+For more information, see
+.BR ip (7),
+glibc and kernel headers.
 .SH BUGS
 The IPv6 extended API as in RFC\ 2292 is currently only partly
 implemented;