diff --git a/phpunit.xml b/phpunit.xml
index fd86a5c..75520cc 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,5 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit
+        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
         colors="true"
         beStrictAboutTestsThatDoNotTestAnything="true"
         beStrictAboutOutputDuringTests="true"