diff --git a/man/systemd-sysusers.xml b/man/systemd-sysusers.xml
index 7da2c55d27..6c9b921f05 100644
--- a/man/systemd-sysusers.xml
+++ b/man/systemd-sysusers.xml
@@ -130,7 +130,8 @@
     <title>See Also</title>
     <para>
       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
-      <citerefentry><refentrytitle>sysusers.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+      <citerefentry><refentrytitle>sysusers.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+      <ulink url="https://systemd.io/UIDS-GIDS">Users, Groups, UIDs and GIDs on systemd systems</ulink>
     </para>
   </refsect1>
 
diff --git a/man/systemd.xml b/man/systemd.xml
index f12956a8a5..e8f022f559 100644
--- a/man/systemd.xml
+++ b/man/systemd.xml
@@ -882,6 +882,9 @@
         for more information.</para></listitem>
       </varlistentry>
     </variablelist>
+
+    <para>For further environment variables understood by systemd and its various components, see <ulink
+    url="https://systemd.io/ENVIRONMENT">Known Environment Variables</ulink>.</para>
   </refsect1>
 
   <refsect1>