diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 828e908..e6c49ee 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4079,6 +4079,12 @@ SELECT pg_stat_get_backend_pid(s.backendid) AS pid,
      </entry>
     </row>
     <row>
+     <entry><literal>writing new heap</literal></entry>
+     <entry>
+       <command>CLUSTER</command> is currently writing the new heap.
+     </entry>
+    </row>
+    <row>
      <entry><literal>swapping relation files</literal></entry>
      <entry>
        The command is currently swapping newly-built files into place.