diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 7bed4f56f0..3b20e73a61 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3376,6 +3376,13 @@ ALTER TABLE measurement ATTACH PARTITION measurement_y2008m02
       </para>
      </listitem>
 
+     <listitem>
+      <para>
+       <command>UPDATE</command> row movement is not supported in the cases
+       where the old row is contained in a foreign table partition.
+      </para>
+     </listitem>
+
      <listitem>
       <para>
        <literal>BEFORE ROW</literal> triggers, if necessary, must be defined