diff --git a/src/conf/schemas/domaincommon.rng b/src/conf/schemas/domaincommon.rng
index 2f07c25430..d15dd33f47 100644
--- a/src/conf/schemas/domaincommon.rng
+++ b/src/conf/schemas/domaincommon.rng
@@ -5658,6 +5658,9 @@
         <optional>
           <ref name="address"/>
         </optional>
+        <optional>
+          <ref name="alias"/>
+        </optional>
       </interleave>
     </element>
   </define>