diff --git a/phpstan.neon b/phpstan.neon
index 8fd15450e65..73fb9c2e8a8 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -386,9 +386,7 @@ parameters:
         -
             identifier: offsetAccess.nonArray
             path: src/PhpParser/NodeTraverser/AbstractImmutableNodeTraverser.php
-        -
-            message: '#Property PhpParser\\Node\\Stmt\\ClassMethod\:\:\$stmts \(array<PhpParser\\Node\\Stmt>\|null\) does not accept array<PhpParser\\Node>#'
-            path: scripts/create-immutable-node-visitor.php
+
         -
             message: '#Property Rector\\PhpParser\\NodeTraverser\\AbstractImmutableNodeTraverser\:\:\$visitors \(list<PhpParser\\NodeVisitor>\) does not accept array<int\|string, PhpParser\\NodeVisitor>#'
             path: src/PhpParser/NodeTraverser/AbstractImmutableNodeTraverser.php
diff --git a/scripts/create-immutable-node-visitor.php b/scripts/create-immutable-node-visitor.php
deleted file mode 100644
index 2ce47c1d635..00000000000
--- a/scripts/create-immutable-node-visitor.php
+++ /dev/null
@@ -1,263 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-use Nette\Utils\FileSystem;
-use PhpParser\Comment\Doc;
-use PhpParser\Modifiers;
-use PhpParser\Node;
-use PhpParser\Node\Arg;
-use PhpParser\Node\Expr\ArrayDimFetch;
-use PhpParser\Node\Expr\Assign;
-use PhpParser\Node\Expr\MethodCall;
-use PhpParser\Node\Expr\PropertyFetch;
-use PhpParser\Node\Expr\Variable;
-use PhpParser\Node\Identifier;
-use PhpParser\Node\Name;
-use PhpParser\Node\Name\FullyQualified;
-use PhpParser\Node\Param;
-use PhpParser\Node\Stmt;
-use PhpParser\Node\Stmt\Class_;
-use PhpParser\Node\Stmt\ClassMethod;
-use PhpParser\Node\Stmt\Expression;
-use PhpParser\Node\Stmt\Foreach_;
-use PhpParser\Node\Stmt\Namespace_;
-use PhpParser\Node\Stmt\Use_;
-use PhpParser\Node\UseItem;
-use PhpParser\NodeTraverser;
-use PhpParser\NodeTraverserInterface;
-use PhpParser\NodeVisitor;
-use PhpParser\NodeVisitorAbstract;
-use PhpParser\ParserFactory;
-use PhpParser\PrettyPrinter\Standard;
-use Webmozart\Assert\Assert;
-
-require __DIR__ . '/../vendor/autoload.php';
-
-// load file contents from vendor
-// modify clas name + namespace
-// add it here as "AbstractImmutableNodeTraverser.php"
-
-$vendorNodeTraverserFilePath = __DIR__ . '/../vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php';
-
-$parserFactory = new ParserFactory();
-$parser = $parserFactory->createForHostVersion();
-$stmts = $parser->parse(FileSystem::read($vendorNodeTraverserFilePath));
-
-Assert::isArray($stmts);
-Assert::allIsInstanceOf($stmts, Stmt::class);
-
-$originalStmts = $stmts;
-
-final class ReplaceForeachThisVisitorNodeVisitor extends NodeVisitorAbstract
-{
-    public function __construct(
-        private readonly string $nodeName
-    ) {
-
-    }
-
-    /**
-     * @return Stmt[]|null
-     */
-    public function enterNode(Node $node): ?array
-    {
-        if (! $node instanceof Foreach_) {
-            return null;
-        }
-
-        if (! $node->expr instanceof PropertyFetch) {
-            return null;
-        }
-
-        $foreachedPropertyFetch = $node->expr;
-        if (! $foreachedPropertyFetch->var instanceof Variable) {
-            return null;
-        }
-
-        if ($foreachedPropertyFetch->var->name !== 'this') {
-            return null;
-        }
-
-        if (! $foreachedPropertyFetch->name instanceof Identifier) {
-            return null;
-        }
-
-        if ($foreachedPropertyFetch->name->toString() !== 'visitors') {
-            return null;
-        }
-
-        // replace $this->visitors with $currentNodeVisitors
-        $currentNodeVisitorsVariable = new Variable(ImmutableNodeTraverserName::CURRENT_NODE_VISITORS);
-        $node->expr = $currentNodeVisitorsVariable;
-
-        // add before foreach: $currentNodeVisitors = $this->getVisitorsForNode($node);
-        $assign = new Assign(
-            $currentNodeVisitorsVariable,
-            new MethodCall(
-                new Variable('this'),
-                ImmutableNodeTraverserName::GET_VISITORS_FOR_NODE_METHOD,
-                [new Arg(new Variable($this->nodeName))]
-            )
-        );
-
-        return [new Expression($assign), $node];
-    }
-}
-
-final class ReplaceThisVisitorsWithThisGetVisitorsNodeVisitor extends NodeVisitorAbstract
-{
-    public function enterNode(Node $node): ?ClassMethod
-    {
-        if (! $node instanceof ClassMethod || $node->stmts === null) {
-            return null;
-        }
-
-        if (! in_array($node->name->toString(), ['traverseArray', 'traverseNode'])) {
-            return null;
-        }
-
-        $traverseArrayNodeName = $node->name->toString() === 'traverseNode' ? 'subNode' : 'node';
-
-        // handle foreach $this->visitors
-        $nodeTraverser = new NodeTraverser();
-        $nodeTraverser->addVisitor(new ReplaceForeachThisVisitorNodeVisitor($traverseArrayNodeName));
-
-        $node->stmts = $nodeTraverser->traverse($node->stmts);
-
-        return $node;
-    }
-}
-
-final class RenameNamespaceNodeVisitor extends NodeVisitorAbstract
-{
-    public function enterNode(Node $node): ?Namespace_
-    {
-        if (! $node instanceof Namespace_) {
-            return null;
-        }
-
-        // add uses for PHPParser nodes as locations are now changed
-        $uses = [
-            new Use_([new UseItem(new Name(NodeTraverserInterface::class))]),
-            new Use_([new UseItem(new Name(NodeVisitor::class))]),
-            new Use_([new UseItem(new Name(Node::class))]),
-        ];
-
-        /** @var Stmt[] $newStmts */
-        $newStmts = array_merge($uses, (array) $node->stmts);
-        $node->stmts = $newStmts;
-
-        $node->name = new Name('Rector\PhpParser\NodeTraverser');
-        return $node;
-    }
-}
-
-final class ReplaceThisVisitorsArrayDimFetchWithCurrentNodeVisitorsNodeVisitor extends NodeVisitorAbstract
-{
-    public function enterNode(Node $node): ?Node
-    {
-        if (! $node instanceof ArrayDimFetch) {
-            return null;
-        }
-
-        if (! $node->var instanceof PropertyFetch) {
-            return null;
-        }
-
-        $propertyFetch = $node->var;
-        if (! $propertyFetch->var instanceof Variable) {
-            return null;
-        }
-
-        if ($propertyFetch->var->name !== 'this') {
-            return null;
-        }
-
-        if (! $propertyFetch->name instanceof Identifier) {
-            return null;
-        }
-
-        if ($propertyFetch->name->toString() !== 'visitors') {
-            return null;
-        }
-
-        if (! $node->dim instanceof Variable) {
-            return null;
-        }
-
-        if ($node->dim->name !== 'visitorIndex') {
-            return null;
-        }
-
-        $node->var = new Variable(ImmutableNodeTraverserName::CURRENT_NODE_VISITORS);
-
-        return $node;
-    }
-}
-
-final class DecorateClassNodeVisitor extends NodeVisitorAbstract
-{
-    public function enterNode(Node $node): ?Class_
-    {
-        if (! $node instanceof Class_) {
-            return null;
-        }
-
-        $node->flags |= Modifiers::ABSTRACT;
-        $node->name = new Identifier('AbstractImmutableNodeTraverser');
-
-        $getVisitorsForNodeClassMethod = new ClassMethod(ImmutableNodeTraverserName::GET_VISITORS_FOR_NODE_METHOD, [
-            'flags' => Modifiers::PUBLIC | Modifiers::ABSTRACT,
-            'params' => [new Param(var: new Variable('node'), type: new FullyQualified(Node::class))],
-            'returnType' => new Name('array'),
-            'stmts' => null,
-        ]);
-
-        // add @return NodeVisitor[] docblock
-        $getVisitorsForNodeClassMethod->setDocComment(new Doc(<<<'DOC'
-/**
- * @return NodeVisitor[]
- */
-DOC
-        ));
-
-        $node->stmts[] = $getVisitorsForNodeClassMethod;
-
-        return $node;
-    }
-}
-
-$nodeTraverser = new NodeTraverser();
-
-$nodeTraverser->addVisitor(new DecorateClassNodeVisitor());
-$nodeTraverser->addVisitor(new ReplaceThisVisitorsWithThisGetVisitorsNodeVisitor());
-$nodeTraverser->addVisitor(new ReplaceThisVisitorsArrayDimFetchWithCurrentNodeVisitorsNodeVisitor());
-$nodeTraverser->addVisitor(new RenameNamespaceNodeVisitor());
-
-$stmts = $nodeTraverser->traverse($stmts);
-
-final class ImmutableNodeTraverserName
-{
-    /**
-     * @var string
-     */
-    public const GET_VISITORS_FOR_NODE_METHOD = 'getVisitorsForNode';
-
-    /**
-     * @var string
-     */
-    public const CURRENT_NODE_VISITORS = 'currentNodeVisitors';
-}
-
-// print node traverser contents
-$standard = new Standard();
-$immutableNodeTraverserFileContents = $standard->printFormatPreserving($stmts, $originalStmts, $parser->getTokens());
-
-// save the file
-FileSystem::write(
-    __DIR__ . '/../src/PhpParser/NodeTraverser/AbstractImmutableNodeTraverser.php',
-    $immutableNodeTraverserFileContents
-);
-
-echo sprintf('New file "%s" was created', 'src/PhpParser/NodeTraverser/AbstractImmutableNodeTraverser.php') . PHP_EOL;
diff --git a/src/PhpParser/NodeTraverser/AbstractImmutableNodeTraverser.php b/src/PhpParser/NodeTraverser/AbstractImmutableNodeTraverser.php
index fe0a16c5fc9..c371781d627 100644
--- a/src/PhpParser/NodeTraverser/AbstractImmutableNodeTraverser.php
+++ b/src/PhpParser/NodeTraverser/AbstractImmutableNodeTraverser.php
@@ -34,14 +34,9 @@ public function __construct(NodeVisitor ...$visitors)
         $this->visitors = $visitors;
     }
 
-    /**
-     * Adds a visitor.
-     *
-     * @param NodeVisitor $visitor Visitor to add
-     */
     public function addVisitor(NodeVisitor $visitor): void
     {
-        $this->visitors[] = $visitor;
+        throw new ShouldNotHappenException('The immutable node traverser does not support adding visitors.');
     }
 
     public function removeVisitor(NodeVisitor $visitor): void
diff --git a/src/PhpParser/NodeTraverser/RectorNodeTraverser.php b/src/PhpParser/NodeTraverser/RectorNodeTraverser.php
index fe61e018022..e5600c2ea33 100644
--- a/src/PhpParser/NodeTraverser/RectorNodeTraverser.php
+++ b/src/PhpParser/NodeTraverser/RectorNodeTraverser.php
@@ -12,6 +12,7 @@
 use Rector\PhpParser\Node\CustomNode\FileWithoutNamespace;
 use Rector\PhpParser\Node\FileNode;
 use Rector\VersionBonding\PhpVersionedFilter;
+use Webmozart\Assert\Assert;
 
 /**
  * @see \Rector\Tests\PhpParser\NodeTraverser\RectorNodeTraverserTest
@@ -50,14 +51,20 @@ public function traverse(array $nodes): array
     /**
      * @param RectorInterface[] $rectors
      * @api used in tests to update the active rules
+     *
+     * @internal Used only in Rector core, not supported outside. Might change any time.
      */
     public function refreshPhpRectors(array $rectors): void
     {
+        Assert::allIsInstanceOf($rectors, RectorInterface::class);
+
         $this->rectors = $rectors;
         $this->visitors = [];
         $this->visitorsPerNodeClass = [];
 
         $this->areNodeVisitorsPrepared = false;
+
+        $this->prepareNodeVisitors();
     }
 
     /**
diff --git a/tests/PhpParser/NodeTraverser/RectorNodeTraverserTest.php b/tests/PhpParser/NodeTraverser/RectorNodeTraverserTest.php
index 428dccdb296..35b4a074abd 100644
--- a/tests/PhpParser/NodeTraverser/RectorNodeTraverserTest.php
+++ b/tests/PhpParser/NodeTraverser/RectorNodeTraverserTest.php
@@ -48,7 +48,7 @@ public function testGetVisitorsForNodeWhenNoVisitorsAvailable(): void
     public function testGetVisitorsForNodeWhenNoVisitorsMatch(): void
     {
         $class = new Class_('test');
-        $this->rectorNodeTraverser->addVisitor($this->ruleUsingFunctionRector);
+        $this->rectorNodeTraverser->refreshPhpRectors([$this->ruleUsingFunctionRector]);
 
         $visitors = $this->rectorNodeTraverser->getVisitorsForNode($class);
 
@@ -58,8 +58,10 @@ public function testGetVisitorsForNodeWhenNoVisitorsMatch(): void
     public function testGetVisitorsForNodeWhenSomeVisitorsMatch(): void
     {
         $class = new Class_('test');
-        $this->rectorNodeTraverser->addVisitor($this->ruleUsingFunctionRector);
-        $this->rectorNodeTraverser->addVisitor($this->ruleUsingClassRector);
+        $this->rectorNodeTraverser->refreshPhpRectors([
+            $this->ruleUsingFunctionRector,
+            $this->ruleUsingClassRector,
+        ]);
 
         $visitors = $this->rectorNodeTraverser->getVisitorsForNode($class);
 
@@ -69,8 +71,10 @@ public function testGetVisitorsForNodeWhenSomeVisitorsMatch(): void
     public function testGetVisitorsForNodeWhenAllVisitorsMatch(): void
     {
         $class = new Class_('test');
-        $this->rectorNodeTraverser->addVisitor($this->ruleUsingClassRector);
-        $this->rectorNodeTraverser->addVisitor($this->ruleUsingClassLikeRector);
+        $this->rectorNodeTraverser->refreshPhpRectors([
+            $this->ruleUsingClassRector,
+            $this->ruleUsingClassLikeRector,
+        ]);
 
         $visitors = $this->rectorNodeTraverser->getVisitorsForNode($class);