diff --git a/wp-includes/default-filters.php b/wp-includes/default-filters.php
index 581e54cc1f..69905be1c3 100644
--- a/wp-includes/default-filters.php
+++ b/wp-includes/default-filters.php
@@ -156,23 +156,23 @@ add_filter( 'list_cats',         'wptexturize' );
 add_filter( 'wp_sprintf', 'wp_sprintf_l', 10, 2 );
 
 // RSS filters
-add_filter( 'the_title_rss',      'strip_tags'      );
-add_filter( 'the_title_rss',      'ent2ncr',      8 );
-add_filter( 'the_title_rss',      'esc_html'        );
-add_filter( 'the_content_rss',    'ent2ncr',      8 );
-add_filter( 'the_content_feed',   'feed_emoji'      );
-add_filter( 'the_excerpt_rss',    'convert_chars'   );
-add_filter( 'the_excerpt_rss',    'ent2ncr',      8 );
-add_filter( 'comment_author_rss', 'ent2ncr',      8 );
-add_filter( 'comment_text_rss',   'ent2ncr',      8 );
-add_filter( 'comment_text_rss',   'esc_html'        );
-add_filter( 'comment_text_rss',   'feed_emoji'      );
-add_filter( 'bloginfo_rss',       'ent2ncr',      8 );
-add_filter( 'the_author',         'ent2ncr',      8 );
-add_filter( 'the_guid',           'esc_url'         );
+add_filter( 'the_title_rss',      'strip_tags'                    );
+add_filter( 'the_title_rss',      'ent2ncr',                    8 );
+add_filter( 'the_title_rss',      'esc_html'                      );
+add_filter( 'the_content_rss',    'ent2ncr',                    8 );
+add_filter( 'the_content_feed',   '_wp_staticize_emoji_for_feeds' );
+add_filter( 'the_excerpt_rss',    'convert_chars'                 );
+add_filter( 'the_excerpt_rss',    'ent2ncr',                    8 );
+add_filter( 'comment_author_rss', 'ent2ncr',                    8 );
+add_filter( 'comment_text_rss',   'ent2ncr',                    8 );
+add_filter( 'comment_text_rss',   'esc_html'                      );
+add_filter( 'comment_text_rss',   '_wp_staticize_emoji_for_feeds' );
+add_filter( 'bloginfo_rss',       'ent2ncr',                    8 );
+add_filter( 'the_author',         'ent2ncr',                    8 );
+add_filter( 'the_guid',           'esc_url'                       );
 
 // Email filters
-add_filter( 'wp_mail', 'mail_emoji' );
+add_filter( 'wp_mail', '_wp_staticize_emoji_for_email' );
 
 // Misc filters
 add_filter( 'option_ping_sites',        'privacy_ping_filter'                 );
diff --git a/wp-includes/feed.php b/wp-includes/feed.php
index feb135e000..dc26188d12 100644
--- a/wp-includes/feed.php
+++ b/wp-includes/feed.php
@@ -653,10 +653,12 @@ function fetch_feed( $url ) {
 /**
  * Convert emoji characters in a feed into static images.
  *
- * @param string $content The content to convert.
+ * @ignore
+ * @since 4.2.0
  *
+ * @param string $content The content to convert.
  * @return The converted content.
  */
-function feed_emoji( $content ) {
+function _wp_staticize_emoji_for_feeds( $content ) {
 	return wp_staticize_emoji( $content, true );
 }
diff --git a/wp-includes/formatting.php b/wp-includes/formatting.php
index 4e7d0da664..6a259069d1 100644
--- a/wp-includes/formatting.php
+++ b/wp-includes/formatting.php
@@ -4192,12 +4192,13 @@ function wp_staticize_emoji( $text ) {
 /**
  * Convert emoji in emails into static images.
  *
+ * @ignore
  * @since 4.2.0
  *
  * @param array $mail The email data array.
  * @return array The email data array, with emoji in the message staticized.
  */
-function mail_emoji( $mail ) {
+function _wp_staticize_emoji_for_email( $mail ) {
 	$mail['message'] = wp_staticize_emoji( $mail['message'], true );
 	return $mail;
 }
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 1a29fc3632..ee770cadc0 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.2-beta1-31790';
+$wp_version = '4.2-beta1-31791';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.