diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index bd687ce9d3..f24a56392a 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -4234,6 +4234,9 @@
         <optional>
           <ref name="address"/>
         </optional>
+        <optional>
+          <ref name="alias"/>
+        </optional>
       </interleave>
     </element>
   </define>