[THRIFT-5760] Update minimal version of php
diff --git a/lib/php/test/Unit/ValidatorTest.php b/lib/php/test/Unit/ValidatorTest.php
index 06f6e55..b125424 100644
--- a/lib/php/test/Unit/ValidatorTest.php
+++ b/lib/php/test/Unit/ValidatorTest.php
@@ -29,7 +29,7 @@
  */
 class ValidatorTest extends BaseValidatorTest
 {
-    public function setUp()
+    public function setUp(): void
     {
         $loader = new ThriftClassLoader();
         $loader->registerNamespace('ThriftTest', __DIR__ . '/../Resources/packages/phpv');