diff --git a/src/Contract/Rector/RectorInterface.php b/src/Contract/Rector/RectorInterface.php
index e060860395d..9be5a353d4b 100644
--- a/src/Contract/Rector/RectorInterface.php
+++ b/src/Contract/Rector/RectorInterface.php
@@ -11,5 +11,5 @@ interface RectorInterface
     /**
      * @param Node $node
      */
-    public function refactor($node): void;
+    public function refactor($node): ?Node;
 }
diff --git a/src/Rector/AbstractRector.php b/src/Rector/AbstractRector.php
index dcdeb515d6d..48ca7a5870e 100644
--- a/src/Rector/AbstractRector.php
+++ b/src/Rector/AbstractRector.php
@@ -10,10 +10,16 @@ use Rector\Contract\Rector\RectorInterface;
 
 abstract class AbstractRector extends NodeVisitorAbstract implements DeprecationInterface, RectorInterface
 {
-    public function enterNode(Node $node): ?int
+    /**
+     * @return int|null|Node
+     */
+    public function enterNode(Node $node)
     {
         if ($this->isCandidate($node)) {
-            $this->refactor($node);
+            if ($newNode = $this->refactor($node)) {
+                return $newNode;
+            }
+
             return NodeTraverser::DONT_TRAVERSE_CHILDREN;
         }
 
diff --git a/src/Rector/Contrib/Nette/FormCallbackRector.php b/src/Rector/Contrib/Nette/FormCallbackRector.php
index b129529d076..5a843afce0f 100644
--- a/src/Rector/Contrib/Nette/FormCallbackRector.php
+++ b/src/Rector/Contrib/Nette/FormCallbackRector.php
@@ -25,6 +25,7 @@ final class FormCallbackRector extends NodeVisitorAbstract implements Deprecatio
     public function enterNode(Node $node): ?int
     {
         if ($this->isCandidate($node)) {
+            return false;
             dump($node); // get next node!
             die;
 
diff --git a/src/Rector/Contrib/Nette/NetteObjectToSmartTraitRector.php b/src/Rector/Contrib/Nette/NetteObjectToSmartTraitRector.php
index 82c99655ce0..26c26a0b421 100644
--- a/src/Rector/Contrib/Nette/NetteObjectToSmartTraitRector.php
+++ b/src/Rector/Contrib/Nette/NetteObjectToSmartTraitRector.php
@@ -56,13 +56,15 @@ final class NetteObjectToSmartTraitRector extends AbstractRector
     /**
      * @param Class_ $classNode
      */
-    public function refactor($classNode): void
+    public function refactor($classNode): ?Node
     {
         // remove parent class
         $classNode->extends = null;
 
         $traitUseNode = $this->createTraitUse('Nette\SmartObject');
         $this->statementGlue->addAsFirstTrait($classNode, $traitUseNode);
+
+        return null;
     }
 
     private function createTraitUse(string $traitName): TraitUse
diff --git a/src/Rector/Contrib/Nette/RemoveConfiguratorConstantsRector.php b/src/Rector/Contrib/Nette/RemoveConfiguratorConstantsRector.php
index 55614ea0739..a2c2eb26bde 100644
--- a/src/Rector/Contrib/Nette/RemoveConfiguratorConstantsRector.php
+++ b/src/Rector/Contrib/Nette/RemoveConfiguratorConstantsRector.php
@@ -6,13 +6,16 @@ use PhpParser\Node;
 use PhpParser\Node\Expr\ClassConstFetch;
 use Rector\Deprecation\SetNames;
 use Rector\Rector\AbstractRector;
+use PhpParser\Node\Scalar\String_;
 
 final class RemoveConfiguratorConstantsRector extends AbstractRector
 {
     public function isCandidate(Node $node): bool
     {
         if ($node instanceof ClassConstFetch) {
-            if ((string) $node->class !== 'Nette\Configurator') {
+            // @todo: check FQN namespace
+            $className = (string) $node->class;
+            if (! in_array($className, ['Nette\Configurator', 'Configurator'], true)) {
                 return false;
             }
 
@@ -29,12 +32,12 @@ final class RemoveConfiguratorConstantsRector extends AbstractRector
     /**
      * @param ClassConstFetch $classConstFetchNode
      */
-    public function refactor($classConstFetchNode): void
+    public function refactor($classConstFetchNode): ?Node
     {
-        dump($classConstFetchNode->name->name);
-        die;
+        $constantName = (string) $classConstFetchNode->name;
+        $string = strtolower($constantName);
 
-        $classConstFetchNode->name->name = $this->getNewConstantName();
+        return new String_($string);
     }
 
     public function getSetName(): string
diff --git a/tests/Rector/Contrib/Nette/RemoveConfiguratorConstantsRector/correct/correct.php.inc b/tests/Rector/Contrib/Nette/RemoveConfiguratorConstantsRector/correct/correct.php.inc
index 5cf52e94219..49cee4c3dd0 100644
--- a/tests/Rector/Contrib/Nette/RemoveConfiguratorConstantsRector/correct/correct.php.inc
+++ b/tests/Rector/Contrib/Nette/RemoveConfiguratorConstantsRector/correct/correct.php.inc
@@ -4,6 +4,6 @@ class ClassWithExternalConstant
 {
     public function getValue()
     {
-        return ClassWithConstants::NEW_CONSTANT;
+        return 'development';
     }
 }
diff --git a/tests/Rector/Contrib/Nette/RemoveConfiguratorConstantsRector/wrong/wrong.php.inc b/tests/Rector/Contrib/Nette/RemoveConfiguratorConstantsRector/wrong/wrong.php.inc
index 76c747b641a..f1abc503dd2 100644
--- a/tests/Rector/Contrib/Nette/RemoveConfiguratorConstantsRector/wrong/wrong.php.inc
+++ b/tests/Rector/Contrib/Nette/RemoveConfiguratorConstantsRector/wrong/wrong.php.inc
@@ -1,9 +1,11 @@
 <?php declare (strict_types=1);
 
+use Nette\Configurator;
+
 class ClassWithExternalConstant
 {
     public function getValue()
     {
-        return ClassWithConstants::OLD_CONSTANT;
+        return Configurator::DEVELOPMENT;
     }
 }