diff --git a/doc/arm/notes.xml b/doc/arm/notes.xml
index 1d3ddd3fc4..6272897de7 100644
--- a/doc/arm/notes.xml
+++ b/doc/arm/notes.xml
@@ -683,6 +683,16 @@
 	  leading to unconstrained memory growth. [RT #46029]
 	</para>
       </listitem>
+      <item>
+	<para>
+	  Some header files included &lt;isc/util.h&gt; incorrectly as
+	  it pollutes with namespace with non ISC_ macros and this should
+	  only be done by explicitly including &lt;isc/util.h&gt;.  This
+	  has been corrected.  Some code made depend on &lt;isc/util.h&gt;
+	  being implicitly included via other header files.  Such
+	  code should explicitly include &lt;isc/util.h&gt;.
+	</para>
+      </item>
     </itemizedlist>
   </section>