Index: src/wp-includes/script-loader.php
===================================================================
--- src/wp-includes/script-loader.php	(revision 51466)
+++ src/wp-includes/script-loader.php	(working copy)
@@ -915,7 +915,7 @@
 	$scripts->add( 'json2', "/wp-includes/js/json2$suffix.js", array(), '2015-05-03' );
 	did_action( 'init' ) && $scripts->add_data( 'json2', 'conditional', 'lt IE 8' );
 
-	$scripts->add( 'underscore', "/wp-includes/js/underscore$dev_suffix.js", array(), '1.8.3', 1 );
+	$scripts->add( 'underscore', "/wp-includes/js/underscore$dev_suffix.js", array(), '1.13.1', 1 );
 	$scripts->add( 'backbone', "/wp-includes/js/backbone$dev_suffix.js", array( 'underscore', 'jquery' ), '1.4.0', 1 );
 
 	$scripts->add( 'wp-util', "/wp-includes/js/wp-util$suffix.js", array( 'underscore', 'jquery' ), false, 1 );