diff --git a/lib/compat/wordpress-6.3/class-wp-classic-to-block-menu-converter.php b/lib/compat/wordpress-6.3/class-gutenberg-classic-to-block-menu-converter.php
similarity index 97%
rename from lib/compat/wordpress-6.3/class-wp-classic-to-block-menu-converter.php
rename to lib/compat/wordpress-6.3/class-gutenberg-classic-to-block-menu-converter.php
index 65c8a6d5bcba74..8677f9abaee170 100644
--- a/lib/compat/wordpress-6.3/class-wp-classic-to-block-menu-converter.php
+++ b/lib/compat/wordpress-6.3/class-gutenberg-classic-to-block-menu-converter.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * WP_Classic_To_Block_Menu_Converter class
+ * Gutenberg_Classic_To_Block_Menu_Converter class
  *
  * @package gutenberg
  * @since 6.3.0
@@ -11,7 +11,7 @@
  *
  * @access public
  */
-class WP_Classic_To_Block_Menu_Converter {
+class Gutenberg_Classic_To_Block_Menu_Converter {
 
 	/**
 	 * Converts a Classic Menu to blocks.
diff --git a/lib/compat/wordpress-6.3/class-wp-navigation-fallback-gutenberg.php b/lib/compat/wordpress-6.3/class-gutenberg-navigation-fallback.php
similarity index 95%
rename from lib/compat/wordpress-6.3/class-wp-navigation-fallback-gutenberg.php
rename to lib/compat/wordpress-6.3/class-gutenberg-navigation-fallback.php
index 0e81a36bb68cd4..91417971e22c73 100644
--- a/lib/compat/wordpress-6.3/class-wp-navigation-fallback-gutenberg.php
+++ b/lib/compat/wordpress-6.3/class-gutenberg-navigation-fallback.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * WP_Navigation_Fallback_Gutenberg class
+ * Gutenberg_Navigation_Fallback class
  *
  * Manages fallback behavior for Navigation menus.
  *
@@ -9,17 +9,12 @@
  * @since 6.3.0
  */
 
-/**
- * Import dependencies.
- */
-require __DIR__ . '/class-wp-classic-to-block-menu-converter.php';
-
 /**
  * Manages fallback behavior for Navigation menus.
  *
  * @access public
  */
-class WP_Navigation_Fallback_Gutenberg {
+class Gutenberg_Navigation_Fallback {
 
 	/**
 	 * Gets (and/or creates) an appropriate fallback Navigation Menu.
@@ -92,7 +87,7 @@ private static function create_classic_menu_fallback() {
 		}
 
 		// If there is a classic menu then convert it to blocks.
-		$classic_nav_menu_blocks = WP_Classic_To_Block_Menu_Converter::convert( $classic_nav_menu );
+		$classic_nav_menu_blocks = Gutenberg_Classic_To_Block_Menu_Converter::convert( $classic_nav_menu );
 
 		if ( empty( $classic_nav_menu_blocks ) ) {
 			return new WP_Error( 'cannot_convert_classic_menu', __( 'Unable to convert Classic Menu to blocks.', 'gutenberg' ) );
diff --git a/lib/compat/wordpress-6.3/class-wp-rest-navigation-fallback-controller.php b/lib/compat/wordpress-6.3/class-gutenberg-rest-navigation-fallback-controller.php
similarity index 94%
rename from lib/compat/wordpress-6.3/class-wp-rest-navigation-fallback-controller.php
rename to lib/compat/wordpress-6.3/class-gutenberg-rest-navigation-fallback-controller.php
index ebc1e5b9ff06a7..2cac70f2ea1c34 100644
--- a/lib/compat/wordpress-6.3/class-wp-rest-navigation-fallback-controller.php
+++ b/lib/compat/wordpress-6.3/class-gutenberg-rest-navigation-fallback-controller.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * WP_REST_Navigation_Fallback_Controller class
+ * Gutenberg_REST_Navigation_Fallback_Controller class
  *
  * REST Controller to create/fetch a fallback Navigation Menu.
  *
@@ -9,15 +9,10 @@
  * @since 6.3.0
  */
 
-/**
- * Import dependencies.
- */
-require __DIR__ . '/class-wp-navigation-fallback-gutenberg.php';
-
 /**
  * REST Controller to fetch a fallback Navigation Block Menu. If needed it creates one.
  */
-class WP_REST_Navigation_Fallback_Controller extends WP_REST_Controller {
+class Gutenberg_REST_Navigation_Fallback_Controller extends WP_REST_Controller {
 
 	/**
 	 * The Post Type for the Controller
@@ -98,7 +93,7 @@ public function get_item_permissions_check( $request ) {
 	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
 	 */
 	public function get_item( $request ) {
-		$post = WP_Navigation_Fallback_Gutenberg::get_fallback();
+		$post = Gutenberg_Navigation_Fallback::get_fallback();
 
 		if ( empty( $post ) ) {
 			return rest_ensure_response( new WP_Error( 'no_fallback_menu', __( 'No fallback menu found.', 'gutenberg' ), array( 'status' => 404 ) ) );
diff --git a/lib/compat/wordpress-6.3/rest-api.php b/lib/compat/wordpress-6.3/rest-api.php
index 87b52ed9b8992a..144ad4d50c83f1 100644
--- a/lib/compat/wordpress-6.3/rest-api.php
+++ b/lib/compat/wordpress-6.3/rest-api.php
@@ -109,3 +109,13 @@ function gutenberg_register_rest_block_patterns() {
 	$block_patterns->register_routes();
 }
 add_action( 'rest_api_init', 'gutenberg_register_rest_block_patterns' );
+
+
+/**
+ * Registers the Navigation Fallbacks REST API routes.
+ */
+function gutenberg_register_rest_navigation_fallbacks() {
+	$editor_settings = new Gutenberg_REST_Navigation_Fallback_Controller();
+	$editor_settings->register_routes();
+}
+add_action( 'rest_api_init', 'gutenberg_register_rest_navigation_fallbacks' );
diff --git a/lib/experimental/rest-api.php b/lib/experimental/rest-api.php
index 4a8bbea1548a6f..2fc7a7af576f82 100644
--- a/lib/experimental/rest-api.php
+++ b/lib/experimental/rest-api.php
@@ -29,16 +29,6 @@ function gutenberg_register_block_editor_settings() {
 add_action( 'rest_api_init', 'gutenberg_register_block_editor_settings' );
 
 
-/**
- * Registers the Navigation Fallbacks REST API routes.
- */
-function gutenberg_register_rest_navigation_fallbacks() {
-	$editor_settings = new WP_REST_Navigation_Fallback_Controller();
-	$editor_settings->register_routes();
-}
-add_action( 'rest_api_init', 'gutenberg_register_rest_navigation_fallbacks' );
-
-
 /**
  * Shim for get_sample_permalink() to add support for auto-draft status.
  *
diff --git a/lib/load.php b/lib/load.php
index 0ef72a48ebdbbe..a390263fa119da 100644
--- a/lib/load.php
+++ b/lib/load.php
@@ -48,7 +48,9 @@ function gutenberg_is_experiment_enabled( $name ) {
 	require_once __DIR__ . '/compat/wordpress-6.3/class-gutenberg-rest-templates-controller-6-3.php';
 	require_once __DIR__ . '/compat/wordpress-6.3/class-gutenberg-rest-global-styles-controller-6-3.php';
 	require_once __DIR__ . '/compat/wordpress-6.3/class-gutenberg-rest-global-styles-revisions-controller-6-3.php';
-	require_once __DIR__ . '/compat/wordpress-6.3/class-wp-rest-navigation-fallback-controller.php';
+	require_once __DIR__ . '/compat/wordpress-6.3/class-gutenberg-classic-to-block-menu-converter.php';
+	require_once __DIR__ . '/compat/wordpress-6.3/class-gutenberg-navigation-fallback.php';
+	require_once __DIR__ . '/compat/wordpress-6.3/class-gutenberg-rest-navigation-fallback-controller.php';
 	require_once __DIR__ . '/compat/wordpress-6.3/rest-api.php';
 	require_once __DIR__ . '/compat/wordpress-6.3/theme-previews.php';
 	require_once __DIR__ . '/compat/wordpress-6.3/navigation-block-preloading.php';
diff --git a/packages/block-library/src/navigation/index.php b/packages/block-library/src/navigation/index.php
index f8f53a93e70fd9..d16de821b47125 100644
--- a/packages/block-library/src/navigation/index.php
+++ b/packages/block-library/src/navigation/index.php
@@ -341,7 +341,7 @@ function block_core_navigation_get_fallback_blocks() {
 	// If `core/page-list` is not registered then return empty blocks.
 	$fallback_blocks = $registry->is_registered( 'core/page-list' ) ? $page_list_fallback : array();
 
-	$navigation_post = WP_Navigation_Fallback_Gutenberg::get_fallback();
+	$navigation_post = Gutenberg_Navigation_Fallback::get_fallback();
 
 	// Use the first non-empty Navigation as fallback if available.
 	if ( $navigation_post ) {
@@ -846,7 +846,7 @@ function block_core_navigation_typographic_presets_backcompatibility( $parsed_bl
  */
 function block_core_navigation_parse_blocks_from_menu_items( $menu_items, $menu_items_by_parent_id ) {
 
-	_deprecated_function( __FUNCTION__, '6.3.0', 'WP_Navigation_Fallback_Gutenberg::parse_blocks_from_menu_items' );
+	_deprecated_function( __FUNCTION__, '6.3.0', 'Gutenberg_Navigation_Fallback::parse_blocks_from_menu_items' );
 
 	if ( empty( $menu_items ) ) {
 		return array();
@@ -895,7 +895,7 @@ function block_core_navigation_parse_blocks_from_menu_items( $menu_items, $menu_
  */
 function block_core_navigation_get_classic_menu_fallback() {
 
-	_deprecated_function( __FUNCTION__, '6.3.0', 'WP_Navigation_Fallback_Gutenberg::get_classic_menu_fallback' );
+	_deprecated_function( __FUNCTION__, '6.3.0', 'Gutenberg_Navigation_Fallback::get_classic_menu_fallback' );
 
 	$classic_nav_menus = wp_get_nav_menus();
 
@@ -938,7 +938,7 @@ static function( $a, $b ) {
  */
 function block_core_navigation_get_classic_menu_fallback_blocks( $classic_nav_menu ) {
 
-	_deprecated_function( __FUNCTION__, '6.3.0', 'WP_Navigation_Fallback_Gutenberg::get_classic_menu_fallback_blocks' );
+	_deprecated_function( __FUNCTION__, '6.3.0', 'Gutenberg_Navigation_Fallback::get_classic_menu_fallback_blocks' );
 
 	// BEGIN: Code that already exists in wp_nav_menu().
 	$menu_items = wp_get_nav_menu_items( $classic_nav_menu->term_id, array( 'update_post_term_cache' => false ) );
@@ -977,7 +977,7 @@ function block_core_navigation_get_classic_menu_fallback_blocks( $classic_nav_me
  */
 function block_core_navigation_maybe_use_classic_menu_fallback() {
 
-	_deprecated_function( __FUNCTION__, '6.3.0', 'WP_Navigation_Fallback_Gutenberg::create_classic_menu_fallback' );
+	_deprecated_function( __FUNCTION__, '6.3.0', 'Gutenberg_Navigation_Fallback::create_classic_menu_fallback' );
 
 	// See if we have a classic menu.
 	$classic_nav_menu = block_core_navigation_get_classic_menu_fallback();
@@ -1020,7 +1020,7 @@ function block_core_navigation_maybe_use_classic_menu_fallback() {
  */
 function block_core_navigation_get_most_recently_published_navigation() {
 
-	_deprecated_function( __FUNCTION__, '6.3.0', 'WP_Navigation_Fallback_Gutenberg::get_most_recently_published_navigation' );
+	_deprecated_function( __FUNCTION__, '6.3.0', 'Gutenberg_Navigation_Fallback::get_most_recently_published_navigation' );
 
 	// Default to the most recently created menu.
 	$parsed_args = array(
diff --git a/phpunit/class-wp-classic-to-block-menu-converter-test.php b/phpunit/class-gutenberg-classic-to-block-menu-converter-test.php
similarity index 90%
rename from phpunit/class-wp-classic-to-block-menu-converter-test.php
rename to phpunit/class-gutenberg-classic-to-block-menu-converter-test.php
index 0d7670d8ec867e..5f0a8ceee52a10 100644
--- a/phpunit/class-wp-classic-to-block-menu-converter-test.php
+++ b/phpunit/class-gutenberg-classic-to-block-menu-converter-test.php
@@ -1,20 +1,20 @@
 <?php
 /**
- * Tests WP_Classic_To_Block_Menu_Converter_Test
+ * Tests Gutenberg_Classic_To_Block_Menu_Converter
  *
  * @package WordPress
  */
 
 /**
- * Tests for the WP_Classic_To_Block_Menu_Converter_Test class.
+ * Tests for the Gutenberg_Classic_To_Block_Menu_Converter_Test class.
  */
-class WP_Classic_To_Block_Menu_Converter_Test extends WP_UnitTestCase {
+class Gutenberg_Classic_To_Block_Menu_Converter_Test extends WP_UnitTestCase {
 
 	/**
 	 * @covers WP_Classic_To_Block_Menu_Converter::get_fallback
 	 */
 	public function test_class_exists() {
-		$this->assertTrue( class_exists( 'WP_Classic_To_Block_Menu_Converter' ) );
+		$this->assertTrue( class_exists( 'Gutenberg_Classic_To_Block_Menu_Converter' ) );
 	}
 
 	/**
@@ -23,7 +23,7 @@ public function test_class_exists() {
 	 */
 	public function test_passing_non_menu_object_to_converter_returns_wp_error( $data ) {
 
-		$result = WP_Classic_To_Block_Menu_Converter::convert( $data );
+		$result = Gutenberg_Classic_To_Block_Menu_Converter::convert( $data );
 
 		$this->assertTrue( is_wp_error( $result ), 'Should be a WP_Error instance' );
 
@@ -88,7 +88,7 @@ public function test_can_convert_classic_menu_to_blocks() {
 
 		$classic_nav_menu = wp_get_nav_menu_object( $menu_id );
 
-		$blocks = WP_Classic_To_Block_Menu_Converter::convert( $classic_nav_menu );
+		$blocks = Gutenberg_Classic_To_Block_Menu_Converter::convert( $classic_nav_menu );
 
 		$this->assertNotEmpty( $blocks );
 
@@ -179,7 +179,7 @@ public function test_does_not_convert_menu_items_with_non_publish_status() {
 
 			$classic_nav_menu = wp_get_nav_menu_object( $menu_id );
 
-			$blocks = WP_Classic_To_Block_Menu_Converter::convert( $classic_nav_menu );
+			$blocks = Gutenberg_Classic_To_Block_Menu_Converter::convert( $classic_nav_menu );
 
 			$this->assertNotEmpty( $blocks );
 
@@ -204,7 +204,7 @@ public function test_returns_empty_array_for_menus_with_no_items() {
 
 		$classic_nav_menu = wp_get_nav_menu_object( $menu_id );
 
-		$blocks = WP_Classic_To_Block_Menu_Converter::convert( $classic_nav_menu );
+		$blocks = Gutenberg_Classic_To_Block_Menu_Converter::convert( $classic_nav_menu );
 
 		$this->assertEmpty( $blocks, 'Result should be empty.' );
 
diff --git a/phpunit/class-wp-navigation-fallback-gutenberg-test.php b/phpunit/class-gutenberg-navigation-fallback-gutenberg-test.php
similarity index 91%
rename from phpunit/class-wp-navigation-fallback-gutenberg-test.php
rename to phpunit/class-gutenberg-navigation-fallback-gutenberg-test.php
index fe32e8a640c078..7b0719950df8b5 100644
--- a/phpunit/class-wp-navigation-fallback-gutenberg-test.php
+++ b/phpunit/class-gutenberg-navigation-fallback-gutenberg-test.php
@@ -1,14 +1,14 @@
 <?php
 /**
- * Tests WP_Navigation_Fallback_Gutenberg
+ * Tests Gutenberg_Navigation_Fallback
  *
  * @package WordPress
  */
 
 /**
- * Tests for the WP_Navigation_Fallback_Gutenberg class.
+ * Tests for the Gutenberg_Navigation_Fallback class.
  */
-class WP_Navigation_Fallback_Gutenberg_Test extends WP_UnitTestCase {
+class Gutenberg_Navigation_Fallback_Test extends WP_UnitTestCase {
 
 	protected static $admin_user;
 	protected static $editor_user;
@@ -29,7 +29,7 @@ public function set_up() {
 	 * @covers WP_REST_Navigation_Fallback_Controller
 	 */
 	public function test_it_exists() {
-		$this->assertTrue( class_exists( 'WP_Navigation_Fallback_Gutenberg' ), 'WP_Navigation_Fallback_Gutenberg class should exist.' );
+		$this->assertTrue( class_exists( 'Gutenberg_Navigation_Fallback' ), 'Gutenberg_Navigation_Fallback class should exist.' );
 	}
 
 
@@ -37,7 +37,7 @@ public function test_it_exists() {
 	 * @covers WP_REST_Navigation_Fallback_Controller::get_fallback
 	 */
 	public function test_should_return_a_default_fallback_navigation_menu_in_absence_of_other_fallbacks() {
-		$data = WP_Navigation_Fallback_Gutenberg::get_fallback();
+		$data = Gutenberg_Navigation_Fallback::get_fallback();
 
 		$this->assertInstanceOf( 'WP_Post', $data, 'Response should be of the correct type.' );
 
@@ -63,7 +63,7 @@ public function test_should_return_a_default_fallback_navigation_menu_with_no_bl
 
 		unregister_block_type( 'core/page-list' );
 
-		$data = WP_Navigation_Fallback_Gutenberg::get_fallback();
+		$data = Gutenberg_Navigation_Fallback::get_fallback();
 
 		$this->assertInstanceOf( 'WP_Post', $data, 'Response should be of the correct type.' );
 
@@ -79,11 +79,11 @@ public function test_should_return_a_default_fallback_navigation_menu_with_no_bl
 	 */
 	public function test_should_handle_consecutive_invocations() {
 		// Invoke the method multiple times to ensure that it doesn't create a new fallback menu on each invocation.
-		WP_Navigation_Fallback_Gutenberg::get_fallback();
-		WP_Navigation_Fallback_Gutenberg::get_fallback();
+		Gutenberg_Navigation_Fallback::get_fallback();
+		Gutenberg_Navigation_Fallback::get_fallback();
 
 		// Assert on the final invocation.
-		$data = WP_Navigation_Fallback_Gutenberg::get_fallback();
+		$data = Gutenberg_Navigation_Fallback::get_fallback();
 
 		$this->assertInstanceOf( 'WP_Post', $data, 'Response should be of the correct type.' );
 
@@ -115,7 +115,7 @@ public function test_should_return_the_most_recently_created_navigation_menu() {
 			)
 		);
 
-		$data = WP_Navigation_Fallback_Gutenberg::get_fallback();
+		$data = Gutenberg_Navigation_Fallback::get_fallback();
 
 		$this->assertInstanceOf( 'WP_Post', $data, 'Response should be of the correct type.' );
 
@@ -147,7 +147,7 @@ public function test_should_return_fallback_navigation_from_existing_classic_men
 			)
 		);
 
-		$data = WP_Navigation_Fallback_Gutenberg::get_fallback();
+		$data = Gutenberg_Navigation_Fallback::get_fallback();
 
 		$this->assertInstanceOf( 'WP_Post', $data, 'Response should be of the correct type.' );
 
@@ -201,7 +201,7 @@ public function test_should_prioritise_fallback_to_classic_menu_in_primary_locat
 		$locations['header']  = $another_menu_id;
 		set_theme_mod( 'nav_menu_locations', $locations );
 
-		$data = WP_Navigation_Fallback_Gutenberg::get_fallback();
+		$data = Gutenberg_Navigation_Fallback::get_fallback();
 
 		$this->assertInstanceOf( 'WP_Post', $data, 'Response should be of the correct type.' );
 
@@ -238,7 +238,7 @@ public function test_should_fallback_to_classic_menu_with_primary_slug() {
 			)
 		);
 
-		$data = WP_Navigation_Fallback_Gutenberg::get_fallback();
+		$data = Gutenberg_Navigation_Fallback::get_fallback();
 
 		$this->assertInstanceOf( 'WP_Post', $data, 'Response should be of the correct type.' );
 
@@ -275,7 +275,7 @@ public function test_should_fallback_to_most_recently_created_classic_menu() {
 			)
 		);
 
-		$data = WP_Navigation_Fallback_Gutenberg::get_fallback();
+		$data = Gutenberg_Navigation_Fallback::get_fallback();
 
 		$this->assertInstanceOf( 'WP_Post', $data, 'Response should be of the correct type.' );
 
@@ -306,7 +306,7 @@ public function test_should_not_create_fallback_from_classic_menu_if_a_navigatio
 			)
 		);
 
-		$data = WP_Navigation_Fallback_Gutenberg::get_fallback();
+		$data = Gutenberg_Navigation_Fallback::get_fallback();
 
 		$this->assertInstanceOf( 'WP_Post', $data, 'Response should be of the correct type.' );
 
diff --git a/phpunit/class-wp-rest-navigation-fallback-controller-test.php b/phpunit/class-gutenberg-rest-navigation-fallback-controller-test.php
similarity index 96%
rename from phpunit/class-wp-rest-navigation-fallback-controller-test.php
rename to phpunit/class-gutenberg-rest-navigation-fallback-controller-test.php
index 1cdedb568a5cd7..14ab8ee0971dd9 100644
--- a/phpunit/class-wp-rest-navigation-fallback-controller-test.php
+++ b/phpunit/class-gutenberg-rest-navigation-fallback-controller-test.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Unit tests covering WP_REST_Navigation_Fallback_Controller functionality.
+ * Unit tests covering Gutenberg_REST_Navigation_Fallback_Controller functionality.
  *
  * Note: that these tests are designed to provide high level coverage only. The majority of the tests
  * are made directly against the WP_Navigation_Fallback_Gutenberg class as this:
@@ -16,7 +16,7 @@
  * @group restapi
  * @group navigation
  */
-class WP_REST_Navigation_Fallback_Controller_Test extends WP_Test_REST_Controller_Testcase {
+class Gutenberg_REST_Navigation_Fallback_Controller_Test extends WP_Test_REST_Controller_Testcase {
 
 	protected static $admin_user;
 	protected static $editor_user;