diff --git a/wp-app.php b/wp-app.php
index b35e0d87ab..dee5cb04d0 100644
--- a/wp-app.php
+++ b/wp-app.php
@@ -12,6 +12,7 @@ define('APP_REQUEST', true);
 require_once('./wp-config.php');
 require_once(ABSPATH . WPINC . '/post-template.php');
 require_once(ABSPATH . WPINC . '/atomlib.php');
+require_once(ABSPATH . WPINC . '/feed.php');
 
 $_SERVER['PATH_INFO'] = preg_replace( '/.*\/wp-app\.php/', '', $_SERVER['REQUEST_URI'] );
 
@@ -784,7 +785,7 @@ EOD;
 <entry xmlns="<?php echo $this->ATOM_NS ?>"
        xmlns:app="<?php echo $this->ATOMPUB_NS ?>" xml:lang="<?php echo get_option('rss_language'); ?>">
 	<id><?php the_guid($GLOBALS['post']->ID); ?></id>
-<?php list($content_type, $content) = $this->prep_content(get_the_title()); ?>
+<?php list($content_type, $content) = prep_atom_text_construct(get_the_title()); ?>
 	<title type="<?php echo $content_type ?>"><?php echo $content ?></title>
 	<updated><?php echo get_post_modified_time('Y-m-d\TH:i:s\Z', true); ?></updated>
 	<published><?php echo get_post_time('Y-m-d\TH:i:s\Z', true); ?></published>
@@ -805,7 +806,7 @@ EOD;
 <?php } else { ?>
 	<link href="<?php the_permalink_rss() ?>" />
 <?php if ( strlen( $GLOBALS['post']->post_content ) ) :
-list($content_type, $content) = $this->prep_content(get_the_content()); ?>
+list($content_type, $content) = prep_atom_text_construct(get_the_content()); ?>
 	<content type="<?php echo $content_type ?>"><?php echo $content ?></content>
 <?php endif; ?>
 <?php } ?>
@@ -813,37 +814,11 @@ list($content_type, $content) = $this->prep_content(get_the_content()); ?>
 <?php foreach(get_the_category() as $category) { ?>
 	<category scheme="<?php bloginfo_rss('home') ?>" term="<?php echo $category->name?>" />
 <?php } ?>
-<?php list($content_type, $content) = $this->prep_content(get_the_excerpt()); ?>
+<?php list($content_type, $content) = prep_atom_text_construct(get_the_excerpt()); ?>
 	<summary type="<?php echo $content_type ?>"><?php echo $content ?></summary>
 </entry>
 <?php }
 
-	function prep_content($data) {
-		if (strpos($data, '<') === false && strpos($data, '&') === false) {
-			return array('text', $data);
-		}
-
-		$parser = xml_parser_create();
-		xml_parse($parser, '<div>' . $data . '</div>', true);
-		$code = xml_get_error_code($parser);
-		xml_parser_free($parser);
-
-		if (!$code) {
-		        if (strpos($data, '<') === false) {
-			        return array('text', $data);
-                        } else {
-			        $data = "<div xmlns='http://www.w3.org/1999/xhtml'>$data</div>";
-			        return array('xhtml', $data);
-                        }
-		}
-
-		if (strpos($data, ']]>') == false) {
-			return array('html', "<![CDATA[$data]]>");
-		} else {
-			return array('html', htmlspecialchars($data));
-		}
-	}
-
 	function ok() {
 		log_app('Status','200: OK');
 		header('Content-Type: text/plain');
diff --git a/wp-includes/feed-atom.php b/wp-includes/feed-atom.php
index 0bb3c5e181..5f5570df19 100644
--- a/wp-includes/feed-atom.php
+++ b/wp-includes/feed-atom.php
@@ -30,15 +30,18 @@ $more = 1;
 			<uri><?php the_author_url()?></uri>
 			<?php endif; ?>
 		</author>
-		<title type="<?php html_type_rss(); ?>"><![CDATA[<?php the_title_rss() ?>]]></title>
+<?php list($content_type, $content) = prep_atom_text_construct(get_the_title()); ?>
+	        <title type="<?php echo $content_type ?>"><?php echo $content ?></title>
 		<link rel="alternate" type="text/html" href="<?php the_permalink_rss() ?>" />
 		<id><?php the_guid(); ?></id>
 		<updated><?php echo get_post_modified_time('Y-m-d\TH:i:s\Z', true); ?></updated>
 		<published><?php echo get_post_time('Y-m-d\TH:i:s\Z', true); ?></published>
 		<?php the_category_rss('atom') ?>
-		<summary type="<?php html_type_rss(); ?>"><![CDATA[<?php the_excerpt_rss(); ?>]]></summary>
+<?php list($content_type, $content) = prep_atom_text_construct(get_the_excerpt()); ?>
+	        <summary type="<?php echo $content_type ?>"><?php echo $content ?></summary>
 <?php if ( !get_option('rss_use_excerpt') ) : ?>
-		<content type="<?php html_type_rss(); ?>" xml:base="<?php the_permalink_rss() ?>"><![CDATA[<?php the_content('', 0, '') ?>]]></content>
+<?php list($content_type, $content) = prep_atom_text_construct(get_the_content()); ?>
+	        <content type="<?php echo $content_type ?>" xml:base="<?php the_permalink_rss()?>"><?php echo $content ?></content>
 <?php endif; ?>
 <?php atom_enclosure(); ?>
 <?php do_action('atom_entry'); ?>
diff --git a/wp-includes/feed.php b/wp-includes/feed.php
index 8f9219c597..bb204ea203 100644
--- a/wp-includes/feed.php
+++ b/wp-includes/feed.php
@@ -250,4 +250,46 @@ function atom_enclosure() {
 	}
 }
 
+/**
+ * prep_atom_text_construct() - determine if given string of data is
+ * type text, html, or xhtml, per RFC 4287 section 3.1.
+ *
+ * In the case of WordPress, text is defined as containing no markup,
+ * xhtml is defined as "well formed", and html as tag soup (i.e., the rest).
+ *
+ * Container div tags are added to xhtml values, per section 3.1.1.3.
+ *
+ * @package WordPress
+ * @subpackage Feed
+ *
+ * @param string $data input string
+ * @return array $result array(type, value)
+ * @link http://www.atomenabled.org/developers/syndication/atom-format-spec.php#rfc.section.3.1
+ */
+function prep_atom_text_construct($data) {
+	if (strpos($data, '<') === false && strpos($data, '&') === false) {
+		return array('text', $data);
+	}
+
+	$parser = xml_parser_create();
+	xml_parse($parser, '<div>' . $data . '</div>', true);
+	$code = xml_get_error_code($parser);
+	xml_parser_free($parser);
+
+	if (!$code) {
+		       if (strpos($data, '<') === false) {
+			       return array('text', $data);
+                       } else {
+			       $data = "<div xmlns='http://www.w3.org/1999/xhtml'>$data</div>";
+			       return array('xhtml', $data);
+                       }
+	}
+
+	if (strpos($data, ']]>') == false) {
+		return array('html', "<![CDATA[$data]]>");
+	} else {
+		return array('html', htmlspecialchars($data));
+	}
+}
+
 ?>