diff --git a/core/scripts/composer/scaffold/composer.json b/core/scripts/composer/scaffold/composer.json
index 55b5018984..907d736253 100644
--- a/core/scripts/composer/scaffold/composer.json
+++ b/core/scripts/composer/scaffold/composer.json
@@ -12,10 +12,8 @@
             "DrupalComposer\\DrupalScaffold\\": "src/"
         }
     },
-    "autoload-dev": {
-        "classmap": [
-            "../../../lib/Drupal/Core/Composer/Composer.php"
-        ]
+    "extra": {
+        "class": "DrupalComposer\\DrupalScaffold\\Plugin"
     },
     "require-dev": {
         "composer/composer": "^1.6.5",
diff --git a/core/scripts/composer/scaffold/phpunit.xml.dist b/core/scripts/composer/scaffold/phpunit.xml.dist
index be419f5dde..ac16a3eafb 100644
--- a/core/scripts/composer/scaffold/phpunit.xml.dist
+++ b/core/scripts/composer/scaffold/phpunit.xml.dist
@@ -7,10 +7,6 @@
     bootstrap="vendor/autoload.php"
     verbose="true"
 >
-    <php>
-        <env name="COMPOSER_ROOT_VERSION" value="999.0.999" />
-    </php>
-
     <testsuites>
         <testsuite name="drupal-scaffold">
             <directory>./tests/</directory>