diff --git a/core/tests/Drupal/Tests/Core/Database/SchemaIntrospectionTestTrait.php b/core/tests/Drupal/Tests/Core/Database/SchemaIntrospectionTestTrait.php
index 5e89de4ca572bc84b14af95a6fa0de75dc59cdcd..b9e4068c278961f530208b29b929edb84c38f5b5 100644
--- a/core/tests/Drupal/Tests/Core/Database/SchemaIntrospectionTestTrait.php
+++ b/core/tests/Drupal/Tests/Core/Database/SchemaIntrospectionTestTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Drupal\Tests\Core\Database;
 
 /**