package.json                      | 2 +-
 src/wp-includes/script-loader.php | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/package.json b/package.json
index f1a7f6f7aa..d58306f42d 100644
--- a/package.json
+++ b/package.json
@@ -93,7 +93,7 @@
 		"@wordpress/url": "2.5.0",
 		"@wordpress/viewport": "2.3.0",
 		"@wordpress/wordcount": "2.2.0",
-		"backbone": "1.3.3",
+		"backbone": "1.4.0",
 		"clipboard": "2.0.4",
 		"element-closest": "^2.0.2",
 		"formdata-polyfill": "3.0.13",
diff --git a/src/wp-includes/script-loader.php b/src/wp-includes/script-loader.php
index a9f78370d9..f92e915be3 100644
--- a/src/wp-includes/script-loader.php
+++ b/src/wp-includes/script-loader.php
@@ -1164,7 +1164,7 @@ function wp_default_scripts( &$scripts ) {
 	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 );
-	$scripts->add( 'backbone', "/wp-includes/js/backbone$dev_suffix.js", array( 'underscore', 'jquery' ), '1.2.3', 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 );
 	did_action( 'init' ) && $scripts->localize(