diff --git a/doc/src/sgml/ref/drop_index.sgml b/doc/src/sgml/ref/drop_index.sgml
index 0aedd71bd6..85cf23bca2 100644
--- a/doc/src/sgml/ref/drop_index.sgml
+++ b/doc/src/sgml/ref/drop_index.sgml
@@ -52,16 +52,18 @@ DROP INDEX [ CONCURRENTLY ] [ IF EXISTS ] <replaceable class="parameter">name</r
      <para>
       There are several caveats to be aware of when using this option.
       Only one index name can be specified, and the <literal>CASCADE</literal> option
       is not supported.  (Thus, an index that supports a <literal>UNIQUE</literal> or
       <literal>PRIMARY KEY</literal> constraint cannot be dropped this way.)
       Also, regular <command>DROP INDEX</command> commands can be
       performed within a transaction block, but
       <command>DROP INDEX CONCURRENTLY</command> cannot.
+      Lastly, indexes on partitioned tables cannot be dropped using this
+      option.
      </para>
      <para>
       For temporary tables, <command>DROP INDEX</command> is always
       non-concurrent, as no other session can access them, and
       non-concurrent index drop is cheaper.
      </para>
     </listitem>
    </varlistentry>