diff --git a/javadoc/xdocs/properties.xml b/javadoc/xdocs/properties.xml
index 944ac876..9a3c7504 100644
--- a/javadoc/xdocs/properties.xml
+++ b/javadoc/xdocs/properties.xml
@@ -210,6 +210,17 @@ tag2.scope=all
             </source>
           </td>
         </tr>
+        <tr>
+          <td>maven.javadoc.additionalparam</td>
+          <td>Yes</td>
+          <td>
+            Specifies additional parameters added to the javadoc command line.
+            <p>Example (sets generated Javadocs encoding to utf-8):</p>
+            <source>
+maven.javadoc.additionalparam=-charset utf-8
+            </source>
+          </td>
+        </tr>
       </table>
     </section>
   </body>