[THRIFT-5760] Update minimal version of php
diff --git a/lib/php/test/Unit/ValidatorTestOop.php b/lib/php/test/Unit/ValidatorTestOop.php
index 79da11e..9558182 100644
--- a/lib/php/test/Unit/ValidatorTestOop.php
+++ b/lib/php/test/Unit/ValidatorTestOop.php
@@ -29,7 +29,7 @@
  */
 class ValidatorTestOop extends BaseValidatorTest
 {
-    public function setUp()
+    public function setUp(): void
     {
         $loader = new ThriftClassLoader();
         $loader->registerNamespace('ThriftTest', __DIR__ . '/../Resources/packages/phpvo');