diff --git a/CHANGELOG.md b/CHANGELOG.md
index 25dbc84..6c2deb5 100755
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,12 @@ You can find and compare releases at the [GitHub release page](https://github.co
 
 ## Unreleased
 
+## v5.6.0
+
+### Added
+
+- Force `T?` over `T|null`
+
 ## v5.5.0
 
 ### Added
diff --git a/config.php b/config.php
index 63443a7..3efed69 100644
--- a/config.php
+++ b/config.php
@@ -44,6 +44,9 @@ function config(Finder $finder, array $ruleOverrides = []): Config
         'no_superfluous_phpdoc_tags' => true,
         'no_useless_else' => true,
         'not_operator_with_successor_space' => true,
+        'nullable_type_declaration' => [
+            'syntax' => 'question_mark',
+        ],
         'operator_linebreak' => [
             'position' => 'beginning',
         ],