diff --git a/src/wp-admin/includes/update-core.php b/src/wp-admin/includes/update-core.php
index 5f5c7a9ab6..51d786fa6d 100644
--- a/src/wp-admin/includes/update-core.php
+++ b/src/wp-admin/includes/update-core.php
@@ -867,6 +867,8 @@ $_old_files = array(
 	'wp-includes/images/wlw',
 	'wp-includes/wlwmanifest.xml',
 	'wp-includes/random_compat',
+	// 6.4
+	'wp-includes/navigation-fallback.php',
 );
 
 /**
diff --git a/src/wp-includes/class-wp-navigation-fallback.php b/src/wp-includes/class-wp-navigation-fallback.php
index bd9583d1fa..59fe023d80 100644
--- a/src/wp-includes/class-wp-navigation-fallback.php
+++ b/src/wp-includes/class-wp-navigation-fallback.php
@@ -17,6 +17,50 @@
  */
 class WP_Navigation_Fallback {
 
+	/**
+	 * Updates the wp_navigation custom post type schema, in order to expose
+	 * additional fields in the embeddable links of WP_REST_Navigation_Fallback_Controller.
+	 *
+	 * The Navigation Fallback endpoint may embed the full Navigation Menu object
+	 * into the response as the `self` link. By default, the Posts Controller
+	 * will only expose a limited subset of fields but the editor requires
+	 * additional fields to be available in order to utilize the menu.
+	 *
+	 * Used with the `rest_wp_navigation_item_schema` hook.
+	 *
+	 * @since 6.4.0
+	 *
+	 * @param array $schema The schema for the `wp_navigation` post.
+	 * @return array The modified schema.
+	 */
+	public static function update_wp_navigation_post_schema( $schema ) {
+		// Expose top level fields.
+		$schema['properties']['status']['context']  = array_merge( $schema['properties']['status']['context'], array( 'embed' ) );
+		$schema['properties']['content']['context'] = array_merge( $schema['properties']['content']['context'], array( 'embed' ) );
+
+		/*
+		 * Exposes sub properties of content field.
+		 * These sub properties aren't exposed by the posts controller by default,
+		 * for requests where context is `embed`.
+		 *
+		 * @see WP_REST_Posts_Controller::get_item_schema()
+		 */
+		$schema['properties']['content']['properties']['raw']['context']           = array_merge( $schema['properties']['content']['properties']['raw']['context'], array( 'embed' ) );
+		$schema['properties']['content']['properties']['rendered']['context']      = array_merge( $schema['properties']['content']['properties']['rendered']['context'], array( 'embed' ) );
+		$schema['properties']['content']['properties']['block_version']['context'] = array_merge( $schema['properties']['content']['properties']['block_version']['context'], array( 'embed' ) );
+
+		/*
+		 * Exposes sub properties of title field.
+		 * These sub properties aren't exposed by the posts controller by default,
+		 * for requests where context is `embed`.
+		 *
+		 * @see WP_REST_Posts_Controller::get_item_schema()
+		 */
+		$schema['properties']['title']['properties']['raw']['context'] = array_merge( $schema['properties']['title']['properties']['raw']['context'], array( 'embed' ) );
+
+		return $schema;
+	}
+
 	/**
 	 * Gets (and/or creates) an appropriate fallback Navigation Menu.
 	 *
@@ -25,7 +69,6 @@ class WP_Navigation_Fallback {
 	 * @return WP_Post|null the fallback Navigation Post or null.
 	 */
 	public static function get_fallback() {
-
 		/**
 		 * Filters whether or not a fallback should be created.
 		 *
diff --git a/src/wp-includes/default-filters.php b/src/wp-includes/default-filters.php
index 99116470d5..4a7787761b 100644
--- a/src/wp-includes/default-filters.php
+++ b/src/wp-includes/default-filters.php
@@ -711,6 +711,9 @@ add_action( 'wp_footer', 'the_block_template_skip_link' );
 add_action( 'setup_theme', 'wp_enable_block_templates' );
 add_action( 'wp_loaded', '_add_template_loader_filters' );
 
+// wp_navigation post type.
+add_filter( 'rest_wp_navigation_item_schema', array( 'WP_Navigation_Fallback', 'update_wp_navigation_post_schema' ) );
+
 // Fluid typography.
 add_filter( 'render_block', 'wp_render_typography_support', 10, 2 );
 
diff --git a/src/wp-includes/navigation-fallback.php b/src/wp-includes/navigation-fallback.php
deleted file mode 100644
index cfd92f07e8..0000000000
--- a/src/wp-includes/navigation-fallback.php
+++ /dev/null
@@ -1,56 +0,0 @@
-<?php
-/**
- * Navigation Fallback
- *
- * Functions required for managing Navigation fallbacks behavior.
- *
- * @package WordPress
- * @since 6.3.0
- */
-
-/**
- * Expose additional fields in the embeddable links of the
- * Navigation Fallback REST endpoint.
- *
- * The endpoint may embed the full Navigation Menu object into the
- * response as the `self` link. By default, the Posts Controller
- * will only expose a limited subset of fields but the editor requires
- * additional fields to be available in order to utilize the menu.
- *
- * @since 6.3.0
- *
- * @param array $schema the schema for the `wp_navigation` post.
- * @return array the modified schema.
- */
-function wp_add_fields_to_navigation_fallback_embedded_links( $schema ) {
-	// Expose top level fields.
-	$schema['properties']['status']['context']  = array_merge( $schema['properties']['status']['context'], array( 'embed' ) );
-	$schema['properties']['content']['context'] = array_merge( $schema['properties']['content']['context'], array( 'embed' ) );
-
-	/*
-	 * Exposes sub properties of content field.
-	 * These sub properties aren't exposed by the posts controller by default,
-	 * for requests where context is `embed`.
-	 *
-	 * @see WP_REST_Posts_Controller::get_item_schema()
-	 */
-	$schema['properties']['content']['properties']['raw']['context']           = array_merge( $schema['properties']['content']['properties']['raw']['context'], array( 'embed' ) );
-	$schema['properties']['content']['properties']['rendered']['context']      = array_merge( $schema['properties']['content']['properties']['rendered']['context'], array( 'embed' ) );
-	$schema['properties']['content']['properties']['block_version']['context'] = array_merge( $schema['properties']['content']['properties']['block_version']['context'], array( 'embed' ) );
-
-	/*
-	 * Exposes sub properties of title field.
-	 * These sub properties aren't exposed by the posts controller by default,
-	 * for requests where context is `embed`.
-	 *
-	 * @see WP_REST_Posts_Controller::get_item_schema()
-	 */
-	$schema['properties']['title']['properties']['raw']['context'] = array_merge( $schema['properties']['title']['properties']['raw']['context'], array( 'embed' ) );
-
-	return $schema;
-}
-
-add_filter(
-	'rest_wp_navigation_item_schema',
-	'wp_add_fields_to_navigation_fallback_embedded_links'
-);
diff --git a/src/wp-settings.php b/src/wp-settings.php
index 528f335cb7..5b1e1205d2 100644
--- a/src/wp-settings.php
+++ b/src/wp-settings.php
@@ -354,7 +354,6 @@ require ABSPATH . WPINC . '/block-supports/position.php';
 require ABSPATH . WPINC . '/block-supports/spacing.php';
 require ABSPATH . WPINC . '/block-supports/typography.php';
 require ABSPATH . WPINC . '/block-supports/settings.php';
-require ABSPATH . WPINC . '/navigation-fallback.php';
 require ABSPATH . WPINC . '/style-engine.php';
 require ABSPATH . WPINC . '/style-engine/class-wp-style-engine.php';
 require ABSPATH . WPINC . '/style-engine/class-wp-style-engine-css-declarations.php';
diff --git a/tests/phpunit/tests/rest-api/rest-navigation-fallback-controller.php b/tests/phpunit/tests/rest-api/rest-navigation-fallback-controller.php
index 43111020e2..efcbe9eb8d 100644
--- a/tests/phpunit/tests/rest-api/rest-navigation-fallback-controller.php
+++ b/tests/phpunit/tests/rest-api/rest-navigation-fallback-controller.php
@@ -152,7 +152,7 @@ class WP_REST_Navigation_Fallback_Controller_Test extends WP_Test_REST_Controlle
 	 *
 	 * @ticket 58557
 	 *
-	 * @covers ::wp_add_fields_to_navigation_fallback_embedded_links
+	 * @covers WP_Navigation_Fallback::update_wp_navigation_post_schema
 	 *
 	 * @since 6.3.0 Added Navigation Fallbacks endpoint.
 	 */