diff --git a/package-lock.json b/package-lock.json
index f807607aa5..c2abc08f34 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -71,7 +71,7 @@
 				"@wordpress/warning": "2.35.1",
 				"@wordpress/widgets": "3.12.12",
 				"@wordpress/wordcount": "3.35.1",
-				"backbone": "1.4.1",
+				"backbone": "1.5.0",
 				"clipboard": "2.0.11",
 				"core-js-url-browser": "3.6.4",
 				"element-closest": "^3.0.2",
@@ -9643,9 +9643,9 @@
 			}
 		},
 		"node_modules/backbone": {
-			"version": "1.4.1",
-			"resolved": "https://registry.npmjs.org/backbone/-/backbone-1.4.1.tgz",
-			"integrity": "sha512-ADy1ztN074YkWbHi8ojJVFe3vAanO/lrzMGZWUClIP7oDD/Pjy2vrASraUP+2EVCfIiTtCW4FChVow01XneivA==",
+			"version": "1.5.0",
+			"resolved": "https://registry.npmjs.org/backbone/-/backbone-1.5.0.tgz",
+			"integrity": "sha512-RPKlstw5NW+rD2X4PnEnvgLhslRnXOugXw2iBloHkPMgOxvakP1/A+tZIGM3qCm8uvZeEf8zMm0uvcK1JwL+IA==",
 			"dependencies": {
 				"underscore": ">=1.8.3"
 			}
diff --git a/package.json b/package.json
index 38a041cae0..89e710a859 100644
--- a/package.json
+++ b/package.json
@@ -138,7 +138,7 @@
 		"@wordpress/warning": "2.35.1",
 		"@wordpress/widgets": "3.12.12",
 		"@wordpress/wordcount": "3.35.1",
-		"backbone": "1.4.1",
+		"backbone": "1.5.0",
 		"clipboard": "2.0.11",
 		"core-js-url-browser": "3.6.4",
 		"element-closest": "^3.0.2",
diff --git a/src/wp-includes/script-loader.php b/src/wp-includes/script-loader.php
index 16c6699a20..229ce1100e 100644
--- a/src/wp-includes/script-loader.php
+++ b/src/wp-includes/script-loader.php
@@ -1013,7 +1013,7 @@ 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(), '1.13.4', 1 );
-	$scripts->add( 'backbone', "/wp-includes/js/backbone$dev_suffix.js", array( 'underscore', 'jquery' ), '1.4.1', 1 );
+	$scripts->add( 'backbone', "/wp-includes/js/backbone$dev_suffix.js", array( 'underscore', 'jquery' ), '1.5.0', 1 );
 
 	$scripts->add( 'wp-util', "/wp-includes/js/wp-util$suffix.js", array( 'underscore', 'jquery' ), false, 1 );
 	did_action( 'init' ) && $scripts->localize(