diff --git a/phpunit.xml b/phpunit.xml
index 696d5d2..e997c7b 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/5.2/phpunit.xsd"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/4.1/phpunit.xsd"
          bootstrap="vendor/autoload.php"
          backupGlobals="false"
          backupStaticAttributes="false"