diff --git a/src/wp-includes/class-wp-customize-nav-menus.php b/src/wp-includes/class-wp-customize-nav-menus.php
index 24384322a0..b4bd0fd0f4 100644
--- a/src/wp-includes/class-wp-customize-nav-menus.php
+++ b/src/wp-includes/class-wp-customize-nav-menus.php
@@ -48,6 +48,11 @@ final class WP_Customize_Nav_Menus {
 		$this->previewed_menus = array();
 		$this->manager         = $manager;
 
+		// Skip useless hooks when the user can't manage nav menus anyway.
+		if ( ! current_user_can( 'edit_theme_options' ) ) {
+			return;
+		}
+
 		add_filter( 'customize_refresh_nonces', array( $this, 'filter_nonces' ) );
 		add_action( 'wp_ajax_load-available-menu-items-customizer', array( $this, 'ajax_load_available_items' ) );
 		add_action( 'wp_ajax_search-available-menu-items-customizer', array( $this, 'ajax_search_available_items' ) );
diff --git a/src/wp-includes/class-wp-customize-widgets.php b/src/wp-includes/class-wp-customize-widgets.php
index 28eaf1283a..ca171b2e57 100644
--- a/src/wp-includes/class-wp-customize-widgets.php
+++ b/src/wp-includes/class-wp-customize-widgets.php
@@ -84,6 +84,11 @@ final class WP_Customize_Widgets {
 	public function __construct( $manager ) {
 		$this->manager = $manager;
 
+		// Skip useless hooks when the user can't manage widgets anyway.
+		if ( ! current_user_can( 'edit_theme_options' ) ) {
+			return;
+		}
+
 		add_filter( 'customize_dynamic_setting_args',          array( $this, 'filter_customize_dynamic_setting_args' ), 10, 2 );
 		add_action( 'after_setup_theme',                       array( $this, 'register_settings' ) );
 		add_action( 'wp_loaded',                               array( $this, 'override_sidebars_widgets_for_theme_switch' ) );
diff --git a/tests/phpunit/tests/customize/widgets.php b/tests/phpunit/tests/customize/widgets.php
index bcb24b22d7..c485b36aa7 100644
--- a/tests/phpunit/tests/customize/widgets.php
+++ b/tests/phpunit/tests/customize/widgets.php
@@ -23,6 +23,9 @@ class Tests_WP_Customize_Widgets extends WP_UnitTestCase {
 	function setUp() {
 		parent::setUp();
 		require_once( ABSPATH . WPINC . '/class-wp-customize-manager.php' );
+
+		$user_id = self::factory()->user->create( array( 'role' => 'administrator' ) );
+		wp_set_current_user( $user_id );
 		$GLOBALS['wp_customize'] = new WP_Customize_Manager();
 		$this->manager = $GLOBALS['wp_customize'];
 
@@ -41,9 +44,6 @@ class Tests_WP_Customize_Widgets extends WP_UnitTestCase {
 		remove_action( 'after_setup_theme', 'twentysixteen_setup' );
 		remove_action( 'customize_register', 'twentysixteen_customize_register', 11 );
 
-		$user_id = self::factory()->user->create( array( 'role' => 'administrator' ) );
-		wp_set_current_user( $user_id );
-
 		$this->backup_registered_sidebars = $GLOBALS['wp_registered_sidebars'];
 	}