diff --git a/js/customize-nav-menus-posts-extensions.js b/js/customize-nav-menus-posts-extensions.js
index b815206..be64671 100644
--- a/js/customize-nav-menus-posts-extensions.js
+++ b/js/customize-nav-menus-posts-extensions.js
@@ -214,6 +214,8 @@ wp.customize.Posts.NavMenusExtensions = (function( api, $ ) {
 	/**
 	 * Rewrite Ajax requests to inject Customizer state.
 	 *
+	 * @todo Remove this once 4.7 is the minimum requirement.
+	 *
 	 * @param {object} options Options.
 	 * @param {string} options.type Type.
 	 * @param {string} options.url URL.
@@ -248,7 +250,11 @@ wp.customize.Posts.NavMenusExtensions = (function( api, $ ) {
 		api.control.each( component.extendNavMenuItemOriginalObjectReference );
 		api.control.bind( 'add', component.extendNavMenuItemOriginalObjectReference );
 		api.bind( 'change', component.watchPostSettingChanges );
-		$.ajaxPrefilter( component.ajaxPrefilterAvailableNavMenuItemRequests );
+
+		// Feature detect WP 4.7, only prefilter available item requests if WP<4.7.
+		if ( ! api.requestChangesetUpdate ) {
+			$.ajaxPrefilter( component.ajaxPrefilterAvailableNavMenuItemRequests );
+		}
 	} );
 
 	return component;
diff --git a/php/class-wp-customize-posts.php b/php/class-wp-customize-posts.php
index 74990d9..40ca97c 100644
--- a/php/class-wp-customize-posts.php
+++ b/php/class-wp-customize-posts.php
@@ -114,14 +114,17 @@ public function __construct( WP_Customize_Manager $manager ) {
 	}
 
 	/**
-	 * Replace core's load and search ajax handlers with forked versions that apply customized state.
+	 * Replace core's load and search ajax handlers with forked versions that apply customized state (only pre-4.7).
+	 *
+	 * @todo Remove this once 4.7 is the minimum requirement.
+	 * @codeCoverageIgnore
 	 *
 	 * @see WP_Customize_Nav_Menus::ajax_load_available_items()
 	 * @see WP_Customize_Nav_Menus::ajax_search_available_items()
 	 * @param WP_Customize_Manager $wp_customize Manager.
 	 */
 	public function replace_nav_menus_ajax_handlers( $wp_customize ) {
-		if ( ! isset( $wp_customize->nav_menus ) ) {
+		if ( ! isset( $wp_customize->nav_menus ) || version_compare( strtok( get_bloginfo( 'version' ), '-' ), '4.7', '>=' ) ) {
 			return;
 		}
 
@@ -1486,6 +1489,7 @@ public function get_select2_item_result( $post ) {
 	 *
 	 * Forked from https://github.com/xwp/wordpress-develop/blob/2515aab6739ea0d2f065eea08ae429889a018fb3/src/wp-includes/class-wp-customize-nav-menus.php#L88-L115
 	 *
+	 * @todo Remove this once 4.7 is the minimum requirement.
 	 * @codeCoverageIgnore
 	 */
 	public function ajax_load_available_items() {
@@ -1526,6 +1530,7 @@ public function ajax_load_available_items() {
 	 *
 	 * Forked from https://github.com/xwp/wordpress-develop/blob/2515aab6739ea0d2f065eea08ae429889a018fb3/src/wp-includes/class-wp-customize-nav-menus.php#L228-L258
 	 *
+	 * @todo Remove this once 4.7 is the minimum requirement.
 	 * @codeCoverageIgnore
 	 */
 	public function ajax_search_available_items() {
diff --git a/tests/php/test-class-wp-customize-posts.php b/tests/php/test-class-wp-customize-posts.php
index b8adbc3..6e3844f 100644
--- a/tests/php/test-class-wp-customize-posts.php
+++ b/tests/php/test-class-wp-customize-posts.php
@@ -121,26 +121,6 @@ public function test_construct() {
 		$this->assertInstanceOf( 'WP_Customize_Posts_Preview', $posts->preview );
 	}
 
-	/**
-	 * Test replace_nav_menus_ajax_handlers.
-	 *
-	 * @covers WP_Customize_Posts::replace_nav_menus_ajax_handlers()
-	 */
-	public function test_replace_nav_menus_ajax_handlers() {
-		$handlers = array(
-			'wp_ajax_load-available-menu-items-customizer' => 'ajax_load_available_items',
-			'wp_ajax_search-available-menu-items-customizer' => 'ajax_search_available_items',
-		);
-		foreach ( $handlers as $action => $method_name ) {
-			$this->assertEquals( 10, has_action( $action, array( $this->wp_customize->nav_menus, $method_name ) ) );
-		}
-		$this->posts->replace_nav_menus_ajax_handlers( $this->wp_customize );
-		foreach ( $handlers as $action => $method_name ) {
-			$this->assertFalse( has_action( $action, array( $this->wp_customize->nav_menus, $method_name ) ) );
-			$this->assertEquals( 10, has_action( $action, array( $this->posts, $method_name ) ) );
-		}
-	}
-
 	/**
 	 * Test add_customize_nonce.
 	 *