diff --git a/src/Symfony/Bridge/PhpUnit/bin/simple-phpunit.php b/src/Symfony/Bridge/PhpUnit/bin/simple-phpunit.php
index ba124f48b11bc..6018299fe1794 100644
--- a/src/Symfony/Bridge/PhpUnit/bin/simple-phpunit.php
+++ b/src/Symfony/Bridge/PhpUnit/bin/simple-phpunit.php
@@ -128,7 +128,7 @@
     $prevRoot = getenv('COMPOSER_ROOT_VERSION');
     putenv("COMPOSER_ROOT_VERSION=$PHPUNIT_VERSION.99");
     // --no-suggest is not in the list to keep compat with composer 1.0, which is shipped with Ubuntu 16.04LTS
-    $exit = proc_close(proc_open("$COMPOSER install --no-dev --prefer-dist --no-progress --ansi", array(), $p, getcwd(), null, array('bypass_shell' => false)));
+    $exit = proc_close(proc_open("$COMPOSER install --no-dev --prefer-dist --no-progress --ansi", array(), $p));
     putenv('COMPOSER_ROOT_VERSION'.(false !== $prevRoot ? '='.$prevRoot : ''));
     if ($exit) {
         exit($exit);