diff --git a/src/Symfony/Component/Config/Definition/ArrayNode.php b/src/Symfony/Component/Config/Definition/ArrayNode.php
index 4a3461119bcfc..96f38dcc9250d 100644
--- a/src/Symfony/Component/Config/Definition/ArrayNode.php
+++ b/src/Symfony/Component/Config/Definition/ArrayNode.php
@@ -68,7 +68,7 @@ protected function preNormalize($value)
     /**
      * Retrieves the children of this node.
      *
-     * @return array The children
+     * @return array<string, NodeInterface>
      */
     public function getChildren()
     {
diff --git a/src/Symfony/Component/Config/Definition/Builder/NodeDefinition.php b/src/Symfony/Component/Config/Definition/Builder/NodeDefinition.php
index 4d3b2f0bb119c..6cc9bc85cc842 100644
--- a/src/Symfony/Component/Config/Definition/Builder/NodeDefinition.php
+++ b/src/Symfony/Component/Config/Definition/Builder/NodeDefinition.php
@@ -127,7 +127,9 @@ public function getNode($forceRootNode = false)
         }
 
         $node = $this->createNode();
-        $node->setAttributes($this->attributes);
+        if ($node instanceof BaseNode) {
+            $node->setAttributes($this->attributes);
+        }
 
         return $node;
     }
diff --git a/src/Symfony/Component/Config/Definition/Dumper/XmlReferenceDumper.php b/src/Symfony/Component/Config/Definition/Dumper/XmlReferenceDumper.php
index 8bd47407fa391..29e4076f97ae8 100644
--- a/src/Symfony/Component/Config/Definition/Dumper/XmlReferenceDumper.php
+++ b/src/Symfony/Component/Config/Definition/Dumper/XmlReferenceDumper.php
@@ -12,6 +12,7 @@
 namespace Symfony\Component\Config\Definition\Dumper;
 
 use Symfony\Component\Config\Definition\ArrayNode;
+use Symfony\Component\Config\Definition\BaseNode;
 use Symfony\Component\Config\Definition\ConfigurationInterface;
 use Symfony\Component\Config\Definition\EnumNode;
 use Symfony\Component\Config\Definition\NodeInterface;
@@ -126,50 +127,52 @@ private function writeNode(NodeInterface $node, int $depth = 0, bool $root = fal
 
             // get attributes and elements
             foreach ($children as $child) {
-                if (!$child instanceof ArrayNode) {
-                    // get attributes
+                if ($child instanceof ArrayNode) {
+                    // get elements
+                    $rootChildren[] = $child;
 
-                    // metadata
-                    $name = str_replace('_', '-', $child->getName());
-                    $value = '%%%%not_defined%%%%'; // use a string which isn't used in the normal world
+                    continue;
+                }
 
-                    // comments
-                    $comments = [];
-                    if ($info = $child->getInfo()) {
-                        $comments[] = $info;
-                    }
+                // get attributes
 
-                    if ($example = $child->getExample()) {
-                        $comments[] = 'Example: '.$example;
-                    }
+                // metadata
+                $name = str_replace('_', '-', $child->getName());
+                $value = '%%%%not_defined%%%%'; // use a string which isn't used in the normal world
 
-                    if ($child->isRequired()) {
-                        $comments[] = 'Required';
-                    }
+                // comments
+                $comments = [];
+                if ($child instanceof BaseNode && $info = $child->getInfo()) {
+                    $comments[] = $info;
+                }
 
-                    if ($child->isDeprecated()) {
-                        $comments[] = sprintf('Deprecated (%s)', $child->getDeprecationMessage($child->getName(), $node->getPath()));
-                    }
+                if ($child instanceof BaseNode && $example = $child->getExample()) {
+                    $comments[] = 'Example: '.$example;
+                }
 
-                    if ($child instanceof EnumNode) {
-                        $comments[] = 'One of '.implode('; ', array_map('json_encode', $child->getValues()));
-                    }
+                if ($child->isRequired()) {
+                    $comments[] = 'Required';
+                }
 
-                    if (\count($comments)) {
-                        $rootAttributeComments[$name] = implode(";\n", $comments);
-                    }
+                if ($child instanceof BaseNode && $child->isDeprecated()) {
+                    $comments[] = sprintf('Deprecated (%s)', $child->getDeprecationMessage($child->getName(), $node->getPath()));
+                }
 
-                    // default values
-                    if ($child->hasDefaultValue()) {
-                        $value = $child->getDefaultValue();
-                    }
+                if ($child instanceof EnumNode) {
+                    $comments[] = 'One of '.implode('; ', array_map('json_encode', $child->getValues()));
+                }
 
-                    // append attribute
-                    $rootAttributes[$name] = $value;
-                } else {
-                    // get elements
-                    $rootChildren[] = $child;
+                if (\count($comments)) {
+                    $rootAttributeComments[$name] = implode(";\n", $comments);
                 }
+
+                // default values
+                if ($child->hasDefaultValue()) {
+                    $value = $child->getDefaultValue();
+                }
+
+                // append attribute
+                $rootAttributes[$name] = $value;
             }
         }
 
diff --git a/src/Symfony/Component/Config/Definition/Dumper/YamlReferenceDumper.php b/src/Symfony/Component/Config/Definition/Dumper/YamlReferenceDumper.php
index 89103efeaf665..c455344d4b5c5 100644
--- a/src/Symfony/Component/Config/Definition/Dumper/YamlReferenceDumper.php
+++ b/src/Symfony/Component/Config/Definition/Dumper/YamlReferenceDumper.php
@@ -12,6 +12,7 @@
 namespace Symfony\Component\Config\Definition\Dumper;
 
 use Symfony\Component\Config\Definition\ArrayNode;
+use Symfony\Component\Config\Definition\BaseNode;
 use Symfony\Component\Config\Definition\ConfigurationInterface;
 use Symfony\Component\Config\Definition\EnumNode;
 use Symfony\Component\Config\Definition\NodeInterface;
@@ -76,7 +77,10 @@ private function writeNode(NodeInterface $node, NodeInterface $parentNode = null
         $default = '';
         $defaultArray = null;
         $children = null;
-        $example = $node->getExample();
+        $example = null;
+        if ($node instanceof BaseNode) {
+            $example = $node->getExample();
+        }
 
         // defaults
         if ($node instanceof ArrayNode) {
@@ -123,7 +127,7 @@ private function writeNode(NodeInterface $node, NodeInterface $parentNode = null
         }
 
         // deprecated?
-        if ($node->isDeprecated()) {
+        if ($node instanceof BaseNode && $node->isDeprecated()) {
             $comments[] = sprintf('Deprecated (%s)', $node->getDeprecationMessage($node->getName(), $parentNode ? $parentNode->getPath() : $node->getPath()));
         }
 
@@ -138,7 +142,7 @@ private function writeNode(NodeInterface $node, NodeInterface $parentNode = null
         $key = $prototypedArray ? '-' : $node->getName().':';
         $text = rtrim(sprintf('%-21s%s %s', $key, $default, $comments), ' ');
 
-        if ($info = $node->getInfo()) {
+        if ($node instanceof BaseNode && $info = $node->getInfo()) {
             $this->writeLine('');
             // indenting multi-line info
             $info = str_replace("\n", sprintf("\n%".($depth * 4).'s# ', ' '), $info);
diff --git a/src/Symfony/Component/Config/Tests/Definition/Dumper/XmlReferenceDumperTest.php b/src/Symfony/Component/Config/Tests/Definition/Dumper/XmlReferenceDumperTest.php
index 1bd60215d7cce..9c2630f1eba92 100644
--- a/src/Symfony/Component/Config/Tests/Definition/Dumper/XmlReferenceDumperTest.php
+++ b/src/Symfony/Component/Config/Tests/Definition/Dumper/XmlReferenceDumperTest.php
@@ -57,6 +57,7 @@ private function getConfigurationAsString()
     node-with-a-looong-name=""
     enum-with-default="this"
     enum=""
+    custom-node="true"
 >
 
     <!-- some info -->
diff --git a/src/Symfony/Component/Config/Tests/Definition/Dumper/YamlReferenceDumperTest.php b/src/Symfony/Component/Config/Tests/Definition/Dumper/YamlReferenceDumperTest.php
index 1166aafb69933..146917aaa7084 100644
--- a/src/Symfony/Component/Config/Tests/Definition/Dumper/YamlReferenceDumperTest.php
+++ b/src/Symfony/Component/Config/Tests/Definition/Dumper/YamlReferenceDumperTest.php
@@ -137,6 +137,7 @@ enum:                 ~ # One of "this"; "that"
 
         # Prototype
         name:                 []
+    custom_node:          true
 
 EOL;
     }
diff --git a/src/Symfony/Component/Config/Tests/Fixtures/Configuration/CustomNode.php b/src/Symfony/Component/Config/Tests/Fixtures/Configuration/CustomNode.php
new file mode 100644
index 0000000000000..1270eb6a68323
--- /dev/null
+++ b/src/Symfony/Component/Config/Tests/Fixtures/Configuration/CustomNode.php
@@ -0,0 +1,49 @@
+<?php
+
+
+namespace Symfony\Component\Config\Tests\Fixtures\Configuration;
+
+use Symfony\Component\Config\Definition\NodeInterface;
+
+class CustomNode implements NodeInterface
+{
+    public function getName()
+    {
+        return 'custom_node';
+    }
+
+    public function getPath()
+    {
+        return 'custom';
+    }
+
+    public function isRequired()
+    {
+        return false;
+    }
+
+    public function hasDefaultValue()
+    {
+        return true;
+    }
+
+    public function getDefaultValue()
+    {
+        return true;
+    }
+
+    public function normalize($value)
+    {
+        return $value;
+    }
+
+    public function merge($leftSide, $rightSide)
+    {
+        return array_merge($leftSide, $rightSide);
+    }
+
+    public function finalize($value)
+    {
+        return $value;
+    }
+}
diff --git a/src/Symfony/Component/Config/Tests/Fixtures/Configuration/CustomNodeDefinition.php b/src/Symfony/Component/Config/Tests/Fixtures/Configuration/CustomNodeDefinition.php
new file mode 100644
index 0000000000000..9783947b9a229
--- /dev/null
+++ b/src/Symfony/Component/Config/Tests/Fixtures/Configuration/CustomNodeDefinition.php
@@ -0,0 +1,14 @@
+<?php
+
+
+namespace Symfony\Component\Config\Tests\Fixtures\Configuration;
+
+use Symfony\Component\Config\Definition\Builder\NodeDefinition;
+
+class CustomNodeDefinition extends NodeDefinition
+{
+    protected function createNode()
+    {
+        return new CustomNode();
+    }
+}
diff --git a/src/Symfony/Component/Config/Tests/Fixtures/Configuration/ExampleConfiguration.php b/src/Symfony/Component/Config/Tests/Fixtures/Configuration/ExampleConfiguration.php
index 21b2345ea01af..1e7a798b552b7 100644
--- a/src/Symfony/Component/Config/Tests/Fixtures/Configuration/ExampleConfiguration.php
+++ b/src/Symfony/Component/Config/Tests/Fixtures/Configuration/ExampleConfiguration.php
@@ -93,6 +93,7 @@ public function getConfigTreeBuilder(): TreeBuilder
                         ->end()
                     ->end()
                 ->end()
+                ->append(new CustomNodeDefinition('acme'))
             ->end()
         ;