diff --git a/phpunit/class-wp-theme-json-resolver-test.php b/phpunit/class-wp-theme-json-resolver-test.php
index f872b251a77840..7b46dc3cd0d4a2 100644
--- a/phpunit/class-wp-theme-json-resolver-test.php
+++ b/phpunit/class-wp-theme-json-resolver-test.php
@@ -43,6 +43,21 @@ class WP_Theme_JSON_Resolver_Gutenberg_Test extends WP_UnitTestCase {
 	 */
 	private static $property_core_orig_value;
 
+	/**
+	 * @var string|null
+	 */
+	private $theme_root;
+
+	/**
+	 * @var array|null
+	 */
+	private $orig_theme_dir;
+
+	/**
+	 * @var array|null
+	 */
+	private $queries;
+
 	public static function set_up_before_class() {
 		parent::set_up_before_class();