diff --git a/ChangeLog-8.5.md b/ChangeLog-8.5.md
index ece37dec0a7..95ec079bf7c 100644
--- a/ChangeLog-8.5.md
+++ b/ChangeLog-8.5.md
@@ -7,6 +7,7 @@ All notable changes of the PHPUnit 8.5 release series are documented in this fil
 ### Changed
 
 * [#4812](https://github.com/sebastianbergmann/phpunit/issues/4812): Do not enforce time limits when a debugging session through DBGp is active
+* [#4835](https://github.com/sebastianbergmann/phpunit/issues/4835): Support for `$GLOBALS['_composer_autoload_path']` introduced in Composer 2.2
 
 ## [8.5.21] - 2021-09-25
 
diff --git a/phpunit b/phpunit
index 4afdd9ad652..d93f85236b6 100755
--- a/phpunit
+++ b/phpunit
@@ -58,15 +58,21 @@ if (!ini_get('date.timezone')) {
     ini_set('date.timezone', 'UTC');
 }
 
-foreach (array(__DIR__ . '/../../autoload.php', __DIR__ . '/../vendor/autoload.php', __DIR__ . '/vendor/autoload.php') as $file) {
-    if (file_exists($file)) {
-        define('PHPUNIT_COMPOSER_INSTALL', $file);
+if (isset($GLOBALS['_composer_autoload_path'])) {
+    define('PHPUNIT_COMPOSER_INSTALL', $GLOBALS['_composer_autoload_path']);
 
-        break;
+    unset($GLOBALS['_composer_autoload_path']);
+} else {
+    foreach (array(__DIR__ . '/../../autoload.php', __DIR__ . '/../vendor/autoload.php', __DIR__ . '/vendor/autoload.php') as $file) {
+        if (file_exists($file)) {
+            define('PHPUNIT_COMPOSER_INSTALL', $file);
+
+            break;
+        }
     }
-}
 
-unset($file);
+    unset($file);
+}
 
 if (!defined('PHPUNIT_COMPOSER_INSTALL')) {
     fwrite(