diff --git a/appendices/migration53.xml b/appendices/migration53.xml
index f620b80d07..76b71b8df1 100644
--- a/appendices/migration53.xml
+++ b/appendices/migration53.xml
@@ -66,6 +66,8 @@
    <listitem>
     <simpara>
      <function>realpath</function> is now fully platform-independent.
+     Consequence of this is that invalid relative paths such as
+     <literal>__FILE__ . "/../x"</literal> does not work anymore.
     </simpara>
    </listitem>
    <listitem>