diff --git a/man/systemd.network.xml b/man/systemd.network.xml
index 5a83314332..19e4f59edd 100644
--- a/man/systemd.network.xml
+++ b/man/systemd.network.xml
@@ -630,6 +630,11 @@
url="https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt">ip-sysctl.txt in the kernel
documentation regarding accept_ra, but note that systemd's setting of
1 (i.e. true) corresponds to kernel's setting of 2.
+
+ Note that if this option is enabled a userspace implementation of the IPv6 RA protocol is
+ used, and the kernel's own implementation remains disabled, since `networkd` needs to know all
+ details supplied in the advertisements, and these are not available from the kernel if the kernel's
+ own implemenation is used.