diff --git a/NEWS b/NEWS
index 39450eea..7fabdf03 100644
--- a/NEWS
+++ b/NEWS
@@ -11,6 +11,7 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
 
 4.1.0, unknown release date
 ! Support proprietary height attribute on table element
+! Support YouTube slideshows that contain /cp/ in their URL.
 
 4.0.0, released 2009-07-07
 # APIs for ConfigSchema subsystem have substantially changed. See
diff --git a/library/HTMLPurifier/Filter/YouTube.php b/library/HTMLPurifier/Filter/YouTube.php
index aca972f6..23df221e 100644
--- a/library/HTMLPurifier/Filter/YouTube.php
+++ b/library/HTMLPurifier/Filter/YouTube.php
@@ -7,13 +7,13 @@ class HTMLPurifier_Filter_YouTube extends HTMLPurifier_Filter
 
     public function preFilter($html, $config, $context) {
         $pre_regex = '#<object[^>]+>.+?'.
-            'http://www.youtube.com/v/([A-Za-z0-9\-_]+).+?</object>#s';
+            'http://www.youtube.com/((?:v|cp)/[A-Za-z0-9\-_=]+).+?</object>#s';
         $pre_replace = '<span class="youtube-embed">\1</span>';
         return preg_replace($pre_regex, $pre_replace, $html);
     }
 
     public function postFilter($html, $config, $context) {
-        $post_regex = '#<span class="youtube-embed">([A-Za-z0-9\-_]+)</span>#';
+        $post_regex = '#<span class="youtube-embed">((?:v|cp)/[A-Za-z0-9\-_=]+)</span>#';
         return preg_replace_callback($post_regex, array($this, 'postFilterCallback'), $html);
     }
 
@@ -24,10 +24,10 @@ class HTMLPurifier_Filter_YouTube extends HTMLPurifier_Filter
     protected function postFilterCallback($matches) {
         $url = $this->armorUrl($matches[1]);
         return '<object width="425" height="350" type="application/x-shockwave-flash" '.
-            'data="http://www.youtube.com/v/'.$url.'">'.
-            '<param name="movie" value="http://www.youtube.com/v/'.$url.'"></param>'.
+            'data="http://www.youtube.com/'.$url.'">'.
+            '<param name="movie" value="http://www.youtube.com/'.$url.'"></param>'.
             '<!--[if IE]>'.
-            '<embed src="http://www.youtube.com/v/'.$url.'"'.
+            '<embed src="http://www.youtube.com/'.$url.'"'.
             'type="application/x-shockwave-flash"'.
             'wmode="transparent" width="425" height="350" />'.
             '<![endif]-->'.
diff --git a/smoketests/preserveYouTube.php b/smoketests/preserveYouTube.php
index 52f04a02..c1b74dbe 100644
--- a/smoketests/preserveYouTube.php
+++ b/smoketests/preserveYouTube.php
@@ -15,7 +15,9 @@ echo '<?xml version="1.0" encoding="UTF-8" ?>';
 <h1>HTML Purifier Preserve YouTube Smoketest</h1>
 <?php
 
-$string = '<object width="425" height="350"><param name="movie" value="http://www.youtube.com/v/BdU--T8rLns"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/BdU--T8rLns" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"></embed></object>';
+$string = '<object width="425" height="350"><param name="movie" value="http://www.youtube.com/v/BdU--T8rLns"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/BdU--T8rLns" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"></embed></object>
+
+<object width="416" height="337"><param name="movie" value="http://www.youtube.com/cp/vjVQa1PpcFNbP_fag8PvopkXZyiXyT0J8U47lw7x5Fc="></param><embed src="http://www.youtube.com/cp/vjVQa1PpcFNbP_fag8PvopkXZyiXyT0J8U47lw7x5Fc=" type="application/x-shockwave-flash" width="416" height="337"></embed></object>';
 
 $regular_purifier = new HTMLPurifier();