--- a/Horde_Http-2.1.7/lib/Horde/Http/Response/Mock.php
+++ b/Horde_Http-2.1.7/lib/Horde/Http/Response/Mock.php
@@ -14,6 +14,7 @@
  * @category Horde
  * @package  Http
  */
+#[AllowDynamicProperties]
 class Horde_Http_Response_Mock extends Horde_Http_Response_Base
 {
     /**
--- a/Horde_Http-2.1.7/test/Horde/Http/phpunit.xml
+++ b/Horde_Http-2.1.7/test/Horde/Http/phpunit.xml
@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" bootstrap="bootstrap.php" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd">
-  <filter>
-    <whitelist>
+  <coverage>
+    <include>
       <directory suffix=".php">../../../lib</directory>
-    </whitelist>
-  </filter>
+    </include>
+  </coverage>
 </phpunit>