diff --git a/wp-includes/formatting.php b/wp-includes/formatting.php
index e6f44c851e..2797741bb2 100644
--- a/wp-includes/formatting.php
+++ b/wp-includes/formatting.php
@@ -4156,6 +4156,16 @@ function print_emoji_detection_script() {
 			'concatemoji' => includes_url( "js/wp-emoji-release.min.js?$version" ),
 		);
 
+		/*
+		 * If you're looking at a src version of this file, you'll see an "include"
+		 * statement below. This is used by the `grunt build` process to directly
+		 * include a minified version of wp-emoji-loader.js, instead of using the
+		 * readfile() method from above.
+		 *
+		 * If you're looking at a build version of this file, you'll see a string of
+		 * minified JavaScript. If you need to debug it, please turn on SCRIPT_DEBUG
+		 * and edit wp-emoji-loader.js directly.
+		 */
 		?>
 		<script type="text/javascript">
 			window._wpemojiSettings = <?php echo wp_json_encode( $settings ); ?>;
diff --git a/wp-includes/version.php b/wp-includes/version.php
index b41e90f23c..ec992fa73c 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.2-beta2-31880';
+$wp_version = '4.2-beta2-31881';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.