diff --git a/doc/src/sgml/event-trigger.sgml b/doc/src/sgml/event-trigger.sgml
index 0219972772..156c4639ab 100644
--- a/doc/src/sgml/event-trigger.sgml
+++ b/doc/src/sgml/event-trigger.sgml
@@ -123,7 +123,7 @@
 
    <table id="event-trigger-by-command-tag">
      <title>Event Trigger Support by Command Tag</title>
-     <tgroup cols="4">
+     <tgroup cols="5">
       <thead>
        <row>
         <entry>command tag</entry>