diff --git a/doc/variables.xml b/doc/variables.xml
index 9dd072a1..0617f874 100644
--- a/doc/variables.xml
+++ b/doc/variables.xml
@@ -4053,6 +4053,16 @@
         <listitem>System name, Linux for example
         <para /></listitem>
     </varlistentry>
+    <varlistentry>
+        <term>
+            <command>
+                <option>sysctlbyname</option>
+            </command>
+            <option>(name)</option>
+        </term>
+        <listitem>Print sysctl value by name. For FreeBSD only.
+        <para /></listitem>
+    </varlistentry>
     <varlistentry>
         <term>
             <command>