diff --git a/core/vendor/phpunit/phpunit/src/Util/PHP/Template/TestCaseMethod.tpl.dist b/core/vendor/phpunit/phpunit/src/Util/PHP/Template/TestCaseMethod.tpl.dist
index 8d714b52a364..5daca63cd095 100644
--- a/core/vendor/phpunit/phpunit/src/Util/PHP/Template/TestCaseMethod.tpl.dist
+++ b/core/vendor/phpunit/phpunit/src/Util/PHP/Template/TestCaseMethod.tpl.dist
@@ -1,4 +1,10 @@
 <?php
+// @see https://github.com/sebastianbergmann/phpunit/pull/1348
+if (!defined('STDOUT')) {
+    define('STDOUT', fopen('php://stdout', 'wb'));
+    define('STDERR', fopen('php://stderr', 'wb'));
+}
+
 {iniSettings}
 ini_set('display_errors', 'stderr');
 set_include_path('{include_path}');