diff --git a/doc/src/sgml/ref/create_statistics.sgml b/doc/src/sgml/ref/create_statistics.sgml
index b43aaf142f..9dfd963959 100644
--- a/doc/src/sgml/ref/create_statistics.sgml
+++ b/doc/src/sgml/ref/create_statistics.sgml
@@ -127,6 +127,12 @@ CREATE STATISTICS [ IF NOT EXISTS ] <replaceable class="parameter">statistics_na
    reading it.  Once created, however, the ownership of the statistics
    object is independent of the underlying table(s).
   </para>
+
+  <para>
+   Extended statistics are not currently used by the planner for selectivity
+   estimations made for table joins.  This limitation will likely be removed
+   in a future version of <productname>PostgreSQL</productname>.
+  </para>
  </refsect1>
 
  <refsect1 id="sql-createstatistics-examples">