diff --git a/src/Symfony/Component/Debug/Tests/Fixtures/Throwing.php b/src/Symfony/Component/Debug/Tests/Fixtures/Throwing.php
index d338ca9d57..21e0aba17d 100644
--- a/src/Symfony/Component/Debug/Tests/Fixtures/Throwing.php
+++ b/src/Symfony/Component/Debug/Tests/Fixtures/Throwing.php
@@ -1,5 +1,3 @@
 <?php
 
-if (!function_exists('__phpunit_run_isolated_test')) {
-    throw new \Exception('boo');
-}
+throw new \Exception('boo');
diff --git a/src/Symfony/Component/Routing/Tests/Fixtures/validresource.php b/src/Symfony/Component/Routing/Tests/Fixtures/validresource.php
index f59a234d65..482c80b29e 100644
--- a/src/Symfony/Component/Routing/Tests/Fixtures/validresource.php
+++ b/src/Symfony/Component/Routing/Tests/Fixtures/validresource.php
@@ -1,8 +1,5 @@
 <?php
 
-if (function_exists('__phpunit_run_isolated_test')) {
-    return;
-}
 /** @var $loader \Symfony\Component\Routing\Loader\PhpFileLoader */
 /** @var \Symfony\Component\Routing\RouteCollection $collection */
 $collection = $loader->import('validpattern.php');