Index: src/wp-admin/includes/class-wp-press-this.php
===================================================================
--- src/wp-admin/includes/class-wp-press-this.php	(revision 32097)
+++ src/wp-admin/includes/class-wp-press-this.php	(working copy)
@@ -1322,7 +1322,7 @@
 
 	<div class="wrapper">
 		<div class="editor-wrapper">
-			<div class="alerts">
+			<div class="alerts" role="alert" aria-live="assertive" aria-relevant="all" aria-atomic="true">
 				<p class="alert is-notice is-hidden should-upgrade-bookmarklet">
 					<?php printf( __( 'You should upgrade <a href="%s" target="_blank">your bookmarklet</a> to the latest version!' ), admin_url( 'tools.php' ) ); ?>
 				</p>