diff --git a/src/wp-admin/includes/file.php b/src/wp-admin/includes/file.php
index 9c0725d1b5779..83dd0acccf7ed 100644
--- a/src/wp-admin/includes/file.php
+++ b/src/wp-admin/includes/file.php
@@ -1779,8 +1779,6 @@ function _unzip_file_pclzip( $file, $to, $needed_dirs = array() ) {
 
 	mbstring_binary_safe_encoding();
 
-	require_once ABSPATH . 'wp-admin/includes/class-pclzip.php';
-
 	$archive = new PclZip( $file );
 
 	$archive_files = $archive->extract( PCLZIP_OPT_EXTRACT_AS_STRING );
diff --git a/src/wp-includes/class-wp-autoload.php b/src/wp-includes/class-wp-autoload.php
index b8ca0ec407f08..55550f808f7e2 100644
--- a/src/wp-includes/class-wp-autoload.php
+++ b/src/wp-includes/class-wp-autoload.php
@@ -25,6 +25,8 @@ final class WP_Autoload {
 		/* Classes in the wp-includes/ folder. */
 		'passwordhash'                                => 'wp-includes/class-phpass.php',
 		'pop3'                                        => 'wp-includes/class-pop3.php',
+		'services_json'                               => 'wp-includes/class-json.php',
+		'services_json_error'                         => 'wp-includes/class-json.php',
 		'walker_categorydropdown'                     => 'wp-includes/class-walker-category-dropdown.php',
 		'walker_category'                             => 'wp-includes/class-walker-category.php',
 		'walker_comment'                              => 'wp-includes/class-walker-comment.php',
diff --git a/tests/phpunit/tests/admin/wpAutomaticUpdater.php b/tests/phpunit/tests/admin/wpAutomaticUpdater.php
index 91ceaa1b38fe7..f8bc6a0904729 100644
--- a/tests/phpunit/tests/admin/wpAutomaticUpdater.php
+++ b/tests/phpunit/tests/admin/wpAutomaticUpdater.php
@@ -25,7 +25,7 @@ class Tests_Admin_WpAutomaticUpdater extends WP_UnitTestCase {
 	 * Sets up shared fixtures.
 	 */
 	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
-		require_once ABSPATH . 'wp-admin/includes/class-wp-automatic-updater.php';
+		require_once ABSPATH . WPINC . '/class-wp-autoload.php';
 		self::$updater = new WP_Automatic_Updater();
 
 		self::$send_plugin_theme_email = new ReflectionMethod( self::$updater, 'send_plugin_theme_email' );
diff --git a/tests/phpunit/tests/admin/wpCommunityEvents.php b/tests/phpunit/tests/admin/wpCommunityEvents.php
index 6b8ccc7f9bc99..811ecf88728f3 100644
--- a/tests/phpunit/tests/admin/wpCommunityEvents.php
+++ b/tests/phpunit/tests/admin/wpCommunityEvents.php
@@ -28,7 +28,7 @@ class Tests_Admin_wpCommunityEvents extends WP_UnitTestCase {
 	public static function set_up_before_class() {
 		parent::set_up_before_class();
 
-		require_once ABSPATH . 'wp-admin/includes/class-wp-community-events.php';
+		require_once ABSPATH . WPINC . '/class-wp-autoload.php';
 	}
 
 	/**
diff --git a/tests/phpunit/tests/admin/wpListTable.php b/tests/phpunit/tests/admin/wpListTable.php
index c28113d99f133..66599a57ca92b 100644
--- a/tests/phpunit/tests/admin/wpListTable.php
+++ b/tests/phpunit/tests/admin/wpListTable.php
@@ -19,7 +19,7 @@ public static function set_up_before_class() {
 
 		parent::set_up_before_class();
 
-		require_once ABSPATH . 'wp-admin/includes/class-wp-list-table.php';
+		require_once ABSPATH . WPINC . '/class-wp-autoload.php';
 
 		$hook_suffix      = '_wp_tests';
 		self::$list_table = new WP_List_Table();
diff --git a/tests/phpunit/tests/admin/wpMediaListTable.php b/tests/phpunit/tests/admin/wpMediaListTable.php
index a130a3250673d..d6d59761d4968 100644
--- a/tests/phpunit/tests/admin/wpMediaListTable.php
+++ b/tests/phpunit/tests/admin/wpMediaListTable.php
@@ -8,7 +8,7 @@ class Tests_Admin_wpMediaListTable extends WP_UnitTestCase {
 	public static function set_up_before_class() {
 		parent::set_up_before_class();
 
-		require_once ABSPATH . 'wp-admin/includes/class-wp-media-list-table.php';
+		require_once ABSPATH . WPINC . '/class-wp-autoload.php';
 	}
 
 	/**
diff --git a/tests/phpunit/tests/adminbar.php b/tests/phpunit/tests/adminbar.php
index aa8043e7ec78a..6bbfd3c2b6102 100644
--- a/tests/phpunit/tests/adminbar.php
+++ b/tests/phpunit/tests/adminbar.php
@@ -17,7 +17,7 @@ class Tests_AdminBar extends WP_UnitTestCase {
 	public static function set_up_before_class() {
 		parent::set_up_before_class();
 
-		require_once ABSPATH . WPINC . '/class-wp-admin-bar.php';
+		require_once ABSPATH . WPINC . '/class-wp-autoload.php';
 	}
 
 	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
@@ -651,7 +651,6 @@ public function test_new_user_link_does_not_exist_for_user_without_create_or_pro
 	 */
 	public function test_customize_link() {
 		global $wp_customize;
-		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
 		$uuid = wp_generate_uuid4();
 		$this->go_to( home_url( "/?customize_changeset_uuid=$uuid" ) );
 		wp_set_current_user( self::$admin_id );
diff --git a/tests/phpunit/tests/ajax/wpAjaxCropImage.php b/tests/phpunit/tests/ajax/wpAjaxCropImage.php
index 3a23f3a425b50..3406c8d185e94 100644
--- a/tests/phpunit/tests/ajax/wpAjaxCropImage.php
+++ b/tests/phpunit/tests/ajax/wpAjaxCropImage.php
@@ -4,8 +4,7 @@
  * Admin Ajax functions to be tested.
  */
 require_once ABSPATH . 'wp-admin/includes/ajax-actions.php';
-require_once ABSPATH . 'wp-admin/includes/class-wp-filesystem-base.php';
-require_once ABSPATH . 'wp-admin/includes/class-wp-filesystem-direct.php';
+require_once ABSPATH . 'wp-includes/class-wp-autoload.php';
 
 /**
  * Class for testing ajax crop image functionality.
diff --git a/tests/phpunit/tests/ajax/wpCustomizeManager.php b/tests/phpunit/tests/ajax/wpCustomizeManager.php
index 15ee1f0d5c639..ff68d9d86c9c8 100644
--- a/tests/phpunit/tests/ajax/wpCustomizeManager.php
+++ b/tests/phpunit/tests/ajax/wpCustomizeManager.php
@@ -53,7 +53,7 @@ public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
 	 */
 	public function set_up() {
 		parent::set_up();
-		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
+		require_once ABSPATH . WPINC . '/class-wp-autoload.php';
 	}
 
 	/**
diff --git a/tests/phpunit/tests/ajax/wpCustomizeNavMenus.php b/tests/phpunit/tests/ajax/wpCustomizeNavMenus.php
index db34c1c5d0383..1db609ab06d80 100644
--- a/tests/phpunit/tests/ajax/wpCustomizeNavMenus.php
+++ b/tests/phpunit/tests/ajax/wpCustomizeNavMenus.php
@@ -52,7 +52,7 @@ public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
 	 */
 	public function set_up() {
 		parent::set_up();
-		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
+		require_once ABSPATH . WPINC . '/class-wp-autoload.php';
 		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
 		global $wp_customize;
 		$this->wp_customize = new WP_Customize_Manager();
diff --git a/tests/phpunit/tests/compat/jsonEncodeDecode.php b/tests/phpunit/tests/compat/jsonEncodeDecode.php
index be51c6022b193..7c311868be0c9 100644
--- a/tests/phpunit/tests/compat/jsonEncodeDecode.php
+++ b/tests/phpunit/tests/compat/jsonEncodeDecode.php
@@ -18,7 +18,7 @@ public function test_json_encode_decode() {
 		$this->setExpectedDeprecated( 'Services_JSON::strlen8' );
 		$this->setExpectedDeprecated( 'Services_JSON::substr8' );
 
-		require_once ABSPATH . WPINC . '/class-json.php';
+		require_once ABSPATH . WPINC . '/class-wp-autoload.php';
 		$json = new Services_JSON();
 
 		// Super basic test to verify Services_JSON is intact and working.
diff --git a/tests/phpunit/tests/customize/control.php b/tests/phpunit/tests/customize/control.php
index d472eacad920a..88feca20a937f 100644
--- a/tests/phpunit/tests/customize/control.php
+++ b/tests/phpunit/tests/customize/control.php
@@ -23,7 +23,7 @@ class Test_WP_Customize_Control extends WP_UnitTestCase {
 	public function set_up() {
 		parent::set_up();
 		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
-		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
+		require_once ABSPATH . WPINC . '/class-wp-autoload.php';
 		$GLOBALS['wp_customize'] = new WP_Customize_Manager();
 		$this->wp_customize      = $GLOBALS['wp_customize'];
 	}
diff --git a/tests/phpunit/tests/customize/custom-css-setting.php b/tests/phpunit/tests/customize/custom-css-setting.php
index 015b6308af306..4f14cf9e5cc07 100644
--- a/tests/phpunit/tests/customize/custom-css-setting.php
+++ b/tests/phpunit/tests/customize/custom-css-setting.php
@@ -29,7 +29,7 @@ class Test_WP_Customize_Custom_CSS_Setting extends WP_UnitTestCase {
 	 */
 	public function set_up() {
 		parent::set_up();
-		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
+		require_once ABSPATH . WPINC . '/class-wp-autoload.php';
 
 		$user_id = self::factory()->user->create(
 			array(
diff --git a/tests/phpunit/tests/customize/manager.php b/tests/phpunit/tests/customize/manager.php
index 9498211a1f4c3..d363c840ac2f6 100644
--- a/tests/phpunit/tests/customize/manager.php
+++ b/tests/phpunit/tests/customize/manager.php
@@ -55,7 +55,7 @@ public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
 	 */
 	public function set_up() {
 		parent::set_up();
-		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
+		require_once ABSPATH . WPINC . '/class-wp-autoload.php';
 		$this->manager = $this->instantiate();
 	}
 
@@ -3638,7 +3638,7 @@ public function test_sanitize_external_header_video_trim() {
 	}
 }
 
-require_once ABSPATH . WPINC . '/class-wp-customize-setting.php';
+require_once ABSPATH . WPINC . '/class-wp-autoload.php';
 
 /**
  * Class Test_Dynamic_Customize_Setting
diff --git a/tests/phpunit/tests/theme.php b/tests/phpunit/tests/theme.php
index 378ed16093339..34e9430a822a4 100644
--- a/tests/phpunit/tests/theme.php
+++ b/tests/phpunit/tests/theme.php
@@ -380,7 +380,7 @@ public function test_wp_keep_alive_customize_changeset_dependent_auto_drafts() {
 			),
 		);
 		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
-		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
+		require_once ABSPATH . WPINC . '/class-wp-autoload.php';
 		$wp_customize = new WP_Customize_Manager();
 		do_action( 'customize_register', $wp_customize );
 
diff --git a/tests/phpunit/tests/widgets.php b/tests/phpunit/tests/widgets.php
index 8f64669c2951b..30a9a316492d8 100644
--- a/tests/phpunit/tests/widgets.php
+++ b/tests/phpunit/tests/widgets.php
@@ -638,7 +638,7 @@ public function test_wp_widget_is_preview() {
 		$this->assertFalse( $widget->is_preview() );
 
 		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
-		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
+		require_once ABSPATH . WPINC . '/class-wp-autoload.php';
 		$wp_customize = new WP_Customize_Manager();
 		$wp_customize->start_previewing_theme();