diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 3a6c18f..df772b5 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -573,7 +573,8 @@
         optional elements. The element <code>hugepages</code> tells
         the hypervisor that the guest should have its memory allocated
         using hugepages instead of the normal native page size. And the
-        optional element <code>nosharepages</code> tells the hypervisor
+        optional element <code>nosharepages</code>
+        (<span class="since">since 1.0.6</span>) tells the hypervisor
         that share pages (memory merge, KSM) should be disabled on guest
         startup.
       </dd>