diff --git a/src/xinput.xml b/src/xinput.xml
index f7239e8..86350de 100644
--- a/src/xinput.xml
+++ b/src/xinput.xml
@@ -1230,6 +1230,7 @@ authorization from the authors.
 
     <request name="XIChangeHierarchy" opcode="43">
         <field type="CARD8" name="num_changes" />
+        <pad bytes="3" />
         <list type="HierarchyChange" name="changes">
             <fieldref>num_changes</fieldref>
         </list>