diff --git a/docbook/reference/en/en-US/modules/proxy.xml b/docbook/reference/en/en-US/modules/proxy.xml
index 20febf0..e707f8d 100755
--- a/docbook/reference/en/en-US/modules/proxy.xml
+++ b/docbook/reference/en/en-US/modules/proxy.xml
@@ -389,7 +389,14 @@ $ java -jar bin/launcher.jar [your-config.json]
</listitem>
</varlistentry>
</variablelist>
- Header field names can be configured using a map of <term>header-names</term> in configuration file.
+ Header field names can be configured using a map of <literal>header-names</literal> in configuration file:
+ <programlisting><![CDATA[
+{
+ "header-names" {
+ "keycloak-subject": "MY_SUBJECT"
+ }
+}
+ ]]></programlisting>
</para>
</section>
</chapter>
\ No newline at end of file
