diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index b5ed1b7939..cab6cf24ee 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3944,8 +3944,10 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
     </para>
 
     <para>
-     Execution-time partition pruning currently occurs for the
+     Execution-time partition pruning currently only occurs for the
      <literal>Append</literal> and <literal>MergeAppend</literal> node types.
+     It is not yet implemented for the <literal>ModifyTable</literal> node
+     type.
     </para>
 
     <para>