diff --git a/wp-includes/js/wp-a11y.js b/wp-includes/js/wp-a11y.js
index 2507cbc2f4ed..7ccdd7540345 100644
--- a/wp-includes/js/wp-a11y.js
+++ b/wp-includes/js/wp-a11y.js
@@ -4,7 +4,8 @@ window.wp = window.wp || {};
 	'use strict';
 
 	var $containerPolite,
-		$containerAssertive;
+		$containerAssertive,
+		previousMessage = '';
 
 	/**
 	 * Update the ARIA live notification area text node.
@@ -23,6 +24,17 @@ window.wp = window.wp || {};
 		// Ensure only text is sent to screen readers.
 		message = $( '<p>' ).html( message ).text();
 
+		/*
+		 * Safari 10+VoiceOver don't announce repeated, identical strings. We use
+		 * a `no-break space` to force them to think identical strings are different.
+		 * See ticket #36853.
+		 */
+		if ( previousMessage === message ) {
+			message = message + '\u00A0';
+		}
+
+		previousMessage = message;
+
 		if ( $containerAssertive && 'assertive' === ariaLive ) {
 			$containerAssertive.text( message );
 		} else if ( $containerPolite ) {
diff --git a/wp-includes/js/wp-a11y.min.js b/wp-includes/js/wp-a11y.min.js
index c0c8929fe84f..3796ce189554 100644
--- a/wp-includes/js/wp-a11y.min.js
+++ b/wp-includes/js/wp-a11y.min.js
@@ -1 +1 @@
-window.wp=window.wp||{},function(a,b){"use strict";function c(a,c){e(),a=b("<p>").html(a).text(),g&&"assertive"===c?g.text(a):f&&f.text(a)}function d(a){a=a||"polite";var c=b("<div>",{id:"wp-a11y-speak-"+a,"aria-live":a,"aria-relevant":"additions text","aria-atomic":"true","class":"screen-reader-text wp-a11y-speak-region"});return b(document.body).append(c),c}function e(){b(".wp-a11y-speak-region").text("")}var f,g;b(document).ready(function(){f=b("#wp-a11y-speak-polite"),g=b("#wp-a11y-speak-assertive"),f.length||(f=d("polite")),g.length||(g=d("assertive"))}),a.a11y=a.a11y||{},a.a11y.speak=c}(window.wp,window.jQuery);
\ No newline at end of file
+window.wp=window.wp||{},function(a,b){"use strict";function c(a,c){e(),a=b("<p>").html(a).text(),h===a&&(a+="\xa0"),h=a,g&&"assertive"===c?g.text(a):f&&f.text(a)}function d(a){a=a||"polite";var c=b("<div>",{id:"wp-a11y-speak-"+a,"aria-live":a,"aria-relevant":"additions text","aria-atomic":"true","class":"screen-reader-text wp-a11y-speak-region"});return b(document.body).append(c),c}function e(){b(".wp-a11y-speak-region").text("")}var f,g,h="";b(document).ready(function(){f=b("#wp-a11y-speak-polite"),g=b("#wp-a11y-speak-assertive"),f.length||(f=d("polite")),g.length||(g=d("assertive"))}),a.a11y=a.a11y||{},a.a11y.speak=c}(window.wp,window.jQuery);
\ No newline at end of file
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 85933eab86db..f43c161010c1 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.8-alpha-40478';
+$wp_version = '4.8-alpha-40479';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.