diff --git a/common/locale/en-US/index.xml b/common/locale/en-US/index.xml
index c533535f..351faadc 100644
--- a/common/locale/en-US/index.xml
+++ b/common/locale/en-US/index.xml
@@ -249,6 +249,7 @@ This file contains a list of all available commands, mappings and options.
     <dt><ex>:extenable</ex></dt> <dd>Enable an extension</dd>
     <dt><ex>:extensions</ex></dt> <dd>List all installed extensions</dd>
     <dt><ex>:extoptions</ex></dt> <dd>Open an extension's preference dialog</dd>
+    <dt><ex>:extupdate</ex></dt> <dd>Update an extension</dd>
     <dt><ex>:exusage</ex></dt> <dd>List all Ex commands with a short description</dd>
     <dt><ex>:finish</ex></dt> <dd>Stop sourcing a script file</dd>
     <dt><ex>:forward</ex></dt> <dd>Go forward in the browser history</dd>