diff --git a/tests/Server/ServerTestCase.php b/tests/Server/ServerTestCase.php
index 431d28d..4ad9698 100644
--- a/tests/Server/ServerTestCase.php
+++ b/tests/Server/ServerTestCase.php
@@ -43,13 +43,13 @@ abstract class ServerTestCase extends TestCase
                     ],
                     'fieldWithSafeException' => [
                         'type' => Type::string(),
-                        'resolve' => function() {
+                        'resolve' => function () {
                             throw new UserError('This is the exception we want');
                         },
                     ],
                     'fieldWithUnsafeException' => [
                         'type' => Type::string(),
-                        'resolve' => function() {
+                        'resolve' => function () {
                             throw new Unsafe('This exception should not be shown to the user');
                         },
                     ],
diff --git a/tests/Server/Unsafe.php b/tests/Server/Unsafe.php
index 5e08918..2eb3742 100644
--- a/tests/Server/Unsafe.php
+++ b/tests/Server/Unsafe.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace GraphQL\Tests\Server;
 
 use GraphQL\Error\ClientAware;