diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 7a2cef3378..39722fe0a9 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,4 +1,6 @@
 <phpunit
+		xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/9.2/phpunit.xsd"
 		bootstrap="tests/phpunit/includes/bootstrap.php"
 		backupGlobals="false"
 		colors="true"
diff --git a/tests/phpunit/multisite.xml b/tests/phpunit/multisite.xml
index fad237b19b..ba92ea5806 100644
--- a/tests/phpunit/multisite.xml
+++ b/tests/phpunit/multisite.xml
@@ -1,4 +1,6 @@
 <phpunit
+		xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/9.2/phpunit.xsd"
 		bootstrap="includes/bootstrap.php"
 		backupGlobals="false"
 		colors="true"