diff --git a/CHANGELOG.md b/CHANGELOG.md
index aceb78f5..5eedbdb6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+- Migrated `rector.php` to the `RectorConfig::configure()` builder.
 - Gathered all repositories in one Symfony application.
 - Changed to vite 7 and rolldown.
 - Added ADRs 008 and 009.
diff --git a/rector.php b/rector.php
index 9773c23c..016c83c6 100644
--- a/rector.php
+++ b/rector.php
@@ -5,22 +5,21 @@
 use Rector\CodeQuality\Rector\Class_\InlineConstructorDefaultToPropertyRector;
 use Rector\Config\RectorConfig;
 use Rector\Doctrine\Set\DoctrineSetList;
+use Rector\Php81\Rector\FuncCall\NullToStrictStringFuncCallArgRector;
 use Rector\Set\ValueObject\LevelSetList;
 use Rector\Symfony\Set\SymfonySetList;
 
-return static function (RectorConfig $rectorConfig): void {
-    $rectorConfig->paths([
+return RectorConfig::configure()
+    ->withPaths([
         __DIR__.'/config',
         __DIR__.'/public',
         __DIR__.'/src',
         __DIR__.'/tests',
-    ]);
-
-    // register a single rule
-    $rectorConfig->rule(InlineConstructorDefaultToPropertyRector::class);
-
-    // define sets of rules
-    $rectorConfig->sets([
+    ])
+    ->withRules([
+        InlineConstructorDefaultToPropertyRector::class,
+    ])
+    ->withSets([
         LevelSetList::UP_TO_PHP_82,
         DoctrineSetList::ANNOTATIONS_TO_ATTRIBUTES,
         DoctrineSetList::DOCTRINE_DBAL_30,
@@ -30,5 +29,13 @@
         SymfonySetList::SYMFONY_63,
         SymfonySetList::SYMFONY_CODE_QUALITY,
         SymfonySetList::SYMFONY_CONSTRUCTOR_INJECTION,
+    ])
+    // The (string) casts Rector wants here would re-introduce the silent
+    // null→"" coercion that 987ae75c removed: the title-modifier path is a
+    // correctness boundary, and on PCRE error the event is omitted with a
+    // log rather than passed through with an unfiltered title.
+    ->withSkip([
+        NullToStrictStringFuncCallArgRector::class => [
+            __DIR__.'/src/Feed/CalendarApiFeedType.php',
+        ],
     ]);
-};