diff --git a/phpunit.xml b/phpunit.xml
index 46f3c9d..9c81ab2 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -2,6 +2,10 @@
 <phpunit bootstrap="vendor/autoload.php"
          colors="true"
          verbose="true">
+    <php>
+        <env name="PHPUNIT_RUNNING" value="1" />
+    </php>
+
     <testsuites>
         <testsuite name="Default">
             <directory>tests</directory>