diff --git a/src/Type/Definition/CustomScalarType.php b/src/Type/Definition/CustomScalarType.php
index 4740b29..49bc8be 100644
--- a/src/Type/Definition/CustomScalarType.php
+++ b/src/Type/Definition/CustomScalarType.php
@@ -9,22 +9,6 @@ use GraphQL\Utils\Utils;
  */
 class CustomScalarType extends ScalarType
 {
-    /**
-     * @var array
-     */
-    public $config;
-
-    /**
-     * CustomScalarType constructor.
-     * @param array $config
-     */
-    function __construct(array $config)
-    {
-        $this->name = $config['name'];
-        $this->config = $config;
-        parent::__construct();
-    }
-
     /**
      * @param mixed $value
      * @return mixed
diff --git a/src/Type/Definition/Directive.php b/src/Type/Definition/Directive.php
index f1c8c55..546f02d 100644
--- a/src/Type/Definition/Directive.php
+++ b/src/Type/Definition/Directive.php
@@ -1,6 +1,8 @@
 <?php
 namespace GraphQL\Type\Definition;
 
+use GraphQL\Language\AST\DirectiveDefinitionNode;
+
 /**
  * Class Directive
  * @package GraphQL\Type\Definition
@@ -157,6 +159,16 @@ class Directive
      */
     public $args;
 
+    /**
+     * @var DirectiveDefinitionNode|null
+     */
+    public $astNode;
+
+    /**
+     * @var array
+     */
+    public $config;
+
     /**
      * Directive constructor.
      * @param array $config
@@ -166,5 +178,6 @@ class Directive
         foreach ($config as $key => $value) {
             $this->{$key} = $value;
         }
+        $this->config = $config;
     }
 }
diff --git a/src/Type/Definition/EnumType.php b/src/Type/Definition/EnumType.php
index b320bd5..120bfee 100644
--- a/src/Type/Definition/EnumType.php
+++ b/src/Type/Definition/EnumType.php
@@ -2,6 +2,7 @@
 namespace GraphQL\Type\Definition;
 
 use GraphQL\Error\InvariantViolation;
+use GraphQL\Language\AST\EnumTypeDefinitionNode;
 use GraphQL\Language\AST\EnumValueNode;
 use GraphQL\Utils\MixedStore;
 use GraphQL\Utils\Utils;
@@ -12,6 +13,11 @@ use GraphQL\Utils\Utils;
  */
 class EnumType extends Type implements InputType, OutputType, LeafType
 {
+    /**
+     * @var EnumTypeDefinitionNode|null
+     */
+    public $astNode;
+
     /**
      * @var EnumValueDefinition[]
      */
@@ -27,11 +33,6 @@ class EnumType extends Type implements InputType, OutputType, LeafType
      */
     private $nameLookup;
 
-    /**
-     * @var array
-     */
-    public $config;
-
     public function __construct($config)
     {
         if (!isset($config['name'])) {
@@ -53,6 +54,7 @@ class EnumType extends Type implements InputType, OutputType, LeafType
 
         $this->name = $config['name'];
         $this->description = isset($config['description']) ? $config['description'] : null;
+        $this->astNode = isset($config['astNode']) ? $config['astNode'] : null;
         $this->config = $config;
     }
 
@@ -91,7 +93,7 @@ class EnumType extends Type implements InputType, OutputType, LeafType
 
     /**
      * @param $name
-     * @return mixed|null
+     * @return EnumValueDefinition|null
      */
     public function getValue($name)
     {
diff --git a/src/Type/Definition/EnumValueDefinition.php b/src/Type/Definition/EnumValueDefinition.php
index 12bbbe1..cd94bab 100644
--- a/src/Type/Definition/EnumValueDefinition.php
+++ b/src/Type/Definition/EnumValueDefinition.php
@@ -1,5 +1,6 @@
 <?php
 namespace GraphQL\Type\Definition;
+use GraphQL\Language\AST\EnumValueDefinitionNode;
 use GraphQL\Utils\Utils;
 
 /**
@@ -28,6 +29,11 @@ class EnumValueDefinition
      */
     public $description;
 
+    /**
+     * @var EnumValueDefinitionNode|null
+     */
+    public $astNode;
+
     /**
      * @var array
      */
@@ -39,6 +45,7 @@ class EnumValueDefinition
         $this->value = isset($config['value']) ? $config['value'] : null;
         $this->deprecationReason = isset($config['deprecationReason']) ? $config['deprecationReason'] : null;
         $this->description = isset($config['description']) ? $config['description'] : null;
+        $this->astNode = isset($config['astNode']) ? $config['astNode'] : null;
 
         $this->config = $config;
     }
diff --git a/src/Type/Definition/FieldArgument.php b/src/Type/Definition/FieldArgument.php
index 3385822..67a567f 100644
--- a/src/Type/Definition/FieldArgument.php
+++ b/src/Type/Definition/FieldArgument.php
@@ -2,6 +2,8 @@
 namespace GraphQL\Type\Definition;
 
 use GraphQL\Error\InvariantViolation;
+use GraphQL\Language\AST\ArgumentNode;
+use GraphQL\Language\AST\InputValueDefinitionNode;
 use GraphQL\Utils\Utils;
 
 
@@ -9,7 +11,6 @@ use GraphQL\Utils\Utils;
  * Class FieldArgument
  *
  * @package GraphQL\Type\Definition
- * @todo Rename to ArgumentNode as it is also applicable to directives, not only fields
  */
 class FieldArgument
 {
@@ -28,6 +29,11 @@ class FieldArgument
      */
     public $description;
 
+    /**
+     * @var InputValueDefinitionNode|null
+     */
+    public $astNode;
+
     /**
      * @var array
      */
@@ -80,6 +86,9 @@ class FieldArgument
                 case 'description':
                     $this->description = $value;
                     break;
+                case 'astNode':
+                    $this->astNode = $value;
+                    break;
             }
         }
         $this->config = $def;
diff --git a/src/Type/Definition/FieldDefinition.php b/src/Type/Definition/FieldDefinition.php
index e3b0ced..8da5b05 100644
--- a/src/Type/Definition/FieldDefinition.php
+++ b/src/Type/Definition/FieldDefinition.php
@@ -1,6 +1,8 @@
 <?php
 namespace GraphQL\Type\Definition;
 use GraphQL\Error\InvariantViolation;
+use GraphQL\Language\AST\FieldDefinitionNode;
+use GraphQL\Language\AST\TypeDefinitionNode;
 use GraphQL\Utils\Utils;
 
 /**
@@ -48,6 +50,11 @@ class FieldDefinition
      */
     public $deprecationReason;
 
+    /**
+     * @var FieldDefinitionNode|null
+     */
+    public $astNode;
+
     /**
      * Original field definition config
      *
@@ -185,6 +192,7 @@ class FieldDefinition
 
         $this->description = isset($config['description']) ? $config['description'] : null;
         $this->deprecationReason = isset($config['deprecationReason']) ? $config['deprecationReason'] : null;
+        $this->astNode = isset($config['astNode']) ? $config['astNode'] : null;
 
         $this->config = $config;
 
diff --git a/src/Type/Definition/InputObjectField.php b/src/Type/Definition/InputObjectField.php
index 732baee..1744e51 100644
--- a/src/Type/Definition/InputObjectField.php
+++ b/src/Type/Definition/InputObjectField.php
@@ -1,5 +1,6 @@
 <?php
 namespace GraphQL\Type\Definition;
+use GraphQL\Language\AST\InputValueDefinitionNode;
 
 /**
  * Class InputObjectField
@@ -27,6 +28,11 @@ class InputObjectField
      */
     public $type;
 
+    /**
+     * @var InputValueDefinitionNode|null
+     */
+    public $astNode;
+
     /**
      * @var array
      */
diff --git a/src/Type/Definition/InputObjectType.php b/src/Type/Definition/InputObjectType.php
index f6166dd..d795630 100644
--- a/src/Type/Definition/InputObjectType.php
+++ b/src/Type/Definition/InputObjectType.php
@@ -2,6 +2,7 @@
 namespace GraphQL\Type\Definition;
 
 use GraphQL\Error\InvariantViolation;
+use GraphQL\Language\AST\InputObjectTypeDefinitionNode;
 use GraphQL\Utils\Utils;
 
 /**
@@ -16,9 +17,9 @@ class InputObjectType extends Type implements InputType
     private $fields;
 
     /**
-     * @var array
+     * @var InputObjectTypeDefinitionNode|null
      */
-    public $config;
+    public $astNode;
 
     /**
      * InputObjectType constructor.
@@ -45,6 +46,7 @@ class InputObjectType extends Type implements InputType
 
         $this->config = $config;
         $this->name = $config['name'];
+        $this->astNode = isset($config['astNode']) ? $config['astNode'] : null;
         $this->description = isset($config['description']) ? $config['description'] : null;
     }
 
diff --git a/src/Type/Definition/InterfaceType.php b/src/Type/Definition/InterfaceType.php
index 1183f32..9d532ec 100644
--- a/src/Type/Definition/InterfaceType.php
+++ b/src/Type/Definition/InterfaceType.php
@@ -2,6 +2,7 @@
 namespace GraphQL\Type\Definition;
 
 use GraphQL\Error\InvariantViolation;
+use GraphQL\Language\AST\InterfaceTypeDefinitionNode;
 use GraphQL\Utils\Utils;
 
 /**
@@ -16,14 +17,9 @@ class InterfaceType extends Type implements AbstractType, OutputType, CompositeT
     private $fields;
 
     /**
-     * @var mixed|null
+     * @var InterfaceTypeDefinitionNode|null
      */
-    public $description;
-
-    /**
-     * @var array
-     */
-    public $config;
+    public $astNode;
 
     /**
      * InterfaceType constructor.
@@ -49,6 +45,7 @@ class InterfaceType extends Type implements AbstractType, OutputType, CompositeT
 
         $this->name = $config['name'];
         $this->description = isset($config['description']) ? $config['description'] : null;
+        $this->astNode = isset($config['astNode']) ? $config['astNode'] : null;
         $this->config = $config;
     }
 
diff --git a/src/Type/Definition/ObjectType.php b/src/Type/Definition/ObjectType.php
index f2b9d70..43d2355 100644
--- a/src/Type/Definition/ObjectType.php
+++ b/src/Type/Definition/ObjectType.php
@@ -2,6 +2,8 @@
 namespace GraphQL\Type\Definition;
 
 use GraphQL\Error\InvariantViolation;
+use GraphQL\Language\AST\ObjectTypeDefinitionNode;
+use GraphQL\Language\AST\TypeExtensionDefinitionNode;
 use GraphQL\Utils\Utils;
 
 
@@ -63,11 +65,14 @@ class ObjectType extends Type implements OutputType, CompositeType
     private $interfaceMap;
 
     /**
-     * Keeping reference of config for late bindings and custom app-level metadata
-     *
-     * @var array
+     * @var ObjectTypeDefinitionNode|null
      */
-    public $config;
+    public $astNode;
+
+    /**
+     * @var TypeExtensionDefinitionNode[]
+     */
+    public $extensionASTNodes;
 
     /**
      * @var callable
@@ -106,6 +111,8 @@ class ObjectType extends Type implements OutputType, CompositeType
         $this->name = $config['name'];
         $this->description = isset($config['description']) ? $config['description'] : null;
         $this->resolveFieldFn = isset($config['resolveField']) ? $config['resolveField'] : null;
+        $this->astNode = isset($config['astNode']) ? $config['astNode'] : null;
+        $this->extensionASTNodes = isset($config['extensionASTNodes']) ? $config['extensionASTNodes'] : [];
         $this->config = $config;
     }
 
diff --git a/src/Type/Definition/ScalarType.php b/src/Type/Definition/ScalarType.php
index 0c05f99..fde81aa 100644
--- a/src/Type/Definition/ScalarType.php
+++ b/src/Type/Definition/ScalarType.php
@@ -1,6 +1,7 @@
 <?php
 namespace GraphQL\Type\Definition;
 
+use GraphQL\Language\AST\ScalarTypeDefinitionNode;
 use GraphQL\Utils\Utils;
 
 /**
@@ -24,13 +25,15 @@ use GraphQL\Utils\Utils;
 abstract class ScalarType extends Type implements OutputType, InputType, LeafType
 {
     /**
-     * ScalarType constructor.
+     * @var ScalarTypeDefinitionNode|null
      */
-    public function __construct()
+    public $astNode;
+
+    function __construct(array $config = [])
     {
-        if (!isset($this->name)) {
-            $this->name = $this->tryInferName();
-        }
+        $this->name = isset($config['name']) ? $config['name'] : $this->tryInferName();
+        $this->astNode = isset($config['astNode']) ? $config['astNode'] : null;
+        $this->config = $config;
 
         Utils::assertValidName($this->name);
     }
diff --git a/src/Type/Definition/Type.php b/src/Type/Definition/Type.php
index aa52df2..2b2c83f 100644
--- a/src/Type/Definition/Type.php
+++ b/src/Type/Definition/Type.php
@@ -2,7 +2,7 @@
 namespace GraphQL\Type\Definition;
 
 use GraphQL\Error\InvariantViolation;
-use GraphQL\Utils\Utils;
+use GraphQL\Language\AST\TypeDefinitionNode;
 
 /**
  * Registry of standard GraphQL types
@@ -202,6 +202,16 @@ abstract class Type implements \JsonSerializable
      */
     public $description;
 
+    /**
+     * @var TypeDefinitionNode|null
+     */
+    public $astNode;
+
+    /**
+     * @var array
+     */
+    public $config;
+
     /**
      * @return null|string
      */
diff --git a/src/Type/Definition/UnionType.php b/src/Type/Definition/UnionType.php
index ebec1b6..49855b7 100644
--- a/src/Type/Definition/UnionType.php
+++ b/src/Type/Definition/UnionType.php
@@ -2,6 +2,7 @@
 namespace GraphQL\Type\Definition;
 
 use GraphQL\Error\InvariantViolation;
+use GraphQL\Language\AST\UnionTypeDefinitionNode;
 use GraphQL\Utils\Utils;
 
 /**
@@ -10,6 +11,11 @@ use GraphQL\Utils\Utils;
  */
 class UnionType extends Type implements AbstractType, OutputType, CompositeType
 {
+    /**
+     * @var UnionTypeDefinitionNode
+     */
+    public $astNode;
+
     /**
      * @var ObjectType[]
      */
@@ -20,11 +26,6 @@ class UnionType extends Type implements AbstractType, OutputType, CompositeType
      */
     private $possibleTypeNames;
 
-    /**
-     * @var array
-     */
-    public $config;
-
     /**
      * UnionType constructor.
      * @param $config
@@ -51,6 +52,7 @@ class UnionType extends Type implements AbstractType, OutputType, CompositeType
          */
         $this->name = $config['name'];
         $this->description = isset($config['description']) ? $config['description'] : null;
+        $this->astNode = isset($config['astNode']) ? $config['astNode'] : null;
         $this->config = $config;
     }
 
diff --git a/src/Type/Schema.php b/src/Type/Schema.php
index 10f1627..dfdebb5 100644
--- a/src/Type/Schema.php
+++ b/src/Type/Schema.php
@@ -3,6 +3,7 @@ namespace GraphQL\Type;
 
 use GraphQL\Error\InvariantViolation;
 use GraphQL\GraphQL;
+use GraphQL\Language\AST\SchemaDefinitionNode;
 use GraphQL\Type\Definition\FieldArgument;
 use GraphQL\Type\Definition\NonNull;
 use GraphQL\Type\Definition\AbstractType;
@@ -357,6 +358,14 @@ class Schema
         return null;
     }
 
+    /**
+     * @return SchemaDefinitionNode
+     */
+    public function getAstNode()
+    {
+        return $this->config->getAstNode();
+    }
+
     /**
      * @param $typeName
      * @return Type
diff --git a/src/Type/SchemaConfig.php b/src/Type/SchemaConfig.php
index 928b993..2b03c37 100644
--- a/src/Type/SchemaConfig.php
+++ b/src/Type/SchemaConfig.php
@@ -1,6 +1,7 @@
 <?php
 namespace GraphQL\Type;
 
+use GraphQL\Language\AST\SchemaDefinitionNode;
 use GraphQL\Type\Definition\Directive;
 use GraphQL\Type\Definition\ObjectType;
 use GraphQL\Type\Definition\Type;
@@ -52,6 +53,11 @@ class SchemaConfig
      */
     public $typeLoader;
 
+    /**
+     * @var SchemaDefinitionNode
+     */
+    public $astNode;
+
     /**
      * Converts an array of options to instance of SchemaConfig
      * (or just returns empty config when array is not passed).
@@ -132,11 +138,38 @@ class SchemaConfig
                 );
                 $config->setTypeLoader($options['typeLoader']);
             }
+
+            if (isset($options['astNode'])) {
+                Utils::invariant(
+                    $options['astNode'] instanceof SchemaDefinitionNode,
+                    'Schema astNode must be an instance of SchemaDefinitionNode but got: %s',
+                    Utils::printSafe($options['typeLoader'])
+                );
+                $config->setAstNode($options['astNode']);
+            }
         }
 
         return $config;
     }
 
+    /**
+     * @return SchemaDefinitionNode
+     */
+    public function getAstNode()
+    {
+        return $this->astNode;
+    }
+
+    /**
+     * @param SchemaDefinitionNode $astNode
+     * @return SchemaConfig
+     */
+    public function setAstNode(SchemaDefinitionNode $astNode)
+    {
+        $this->astNode = $astNode;
+        return $this;
+    }
+
     /**
      * @api
      * @param ObjectType $query
diff --git a/src/Utils/BuildSchema.php b/src/Utils/BuildSchema.php
index 6ebd6c9..d75a11f 100644
--- a/src/Utils/BuildSchema.php
+++ b/src/Utils/BuildSchema.php
@@ -241,6 +241,7 @@ class BuildSchema
                 return $this->typeDefNamed($name);
             },
             'directives' => $directives,
+            'astNode' => $schemaDef,
             'types' => function() {
                 $types = [];
                 foreach ($this->nodeMap as $name => $def) {
@@ -264,6 +265,7 @@ class BuildSchema
                 return $node->value;
             }),
             'args' => $directiveNode->arguments ? FieldArgument::createMap($this->makeInputValues($directiveNode->arguments)) : null,
+            'astNode' => $directiveNode
         ]);
     }
 
@@ -428,7 +430,8 @@ class BuildSchema
             },
             'interfaces' => function() use ($def) {
                 return $this->makeImplementedInterfaces($def);
-            }
+            },
+            'astNode' => $def
         ];
     }
 
@@ -444,7 +447,8 @@ class BuildSchema
                     'type' => $this->produceOutputType($field->type),
                     'description' => $this->getDescription($field),
                     'args' => $this->makeInputValues($field->arguments),
-                    'deprecationReason' => $this->getDeprecationReason($field)
+                    'deprecationReason' => $this->getDeprecationReason($field),
+                    'astNode' => $field
                 ];
             }
         );
@@ -472,7 +476,8 @@ class BuildSchema
                 $config = [
                     'name' => $value->name->value,
                     'type' => $type,
-                    'description' => $this->getDescription($value)
+                    'description' => $this->getDescription($value),
+                    'astNode' => $value
                 ];
                 if (isset($value->defaultValue)) {
                     $config['defaultValue'] = AST::valueFromAST($value->defaultValue, $type);
@@ -491,6 +496,7 @@ class BuildSchema
             'fields' => function() use ($def) {
                 return $this->makeFieldDefMap($def);
             },
+            'astNode' => $def,
             'resolveType' => function() {
                 $this->cannotExecuteSchema();
             }
@@ -502,6 +508,7 @@ class BuildSchema
         return [
             'name' => $def->name->value,
             'description' => $this->getDescription($def),
+            'astNode' => $def,
             'values' => Utils::keyValMap(
                 $def->values,
                 function($enumValue) {
@@ -510,7 +517,8 @@ class BuildSchema
                 function($enumValue) {
                     return [
                         'description' => $this->getDescription($enumValue),
-                        'deprecationReason' => $this->getDeprecationReason($enumValue)
+                        'deprecationReason' => $this->getDeprecationReason($enumValue),
+                        'astNode' => $enumValue
                     ];
                 }
             )
@@ -525,6 +533,7 @@ class BuildSchema
             'types' => Utils::map($def->types, function($typeNode) {
                 return $this->produceObjectType($typeNode);
             }),
+            'astNode' => $def,
             'resolveType' => [$this, 'cannotExecuteSchema']
         ];
     }
@@ -534,6 +543,7 @@ class BuildSchema
         return [
             'name' => $def->name->value,
             'description' => $this->getDescription($def),
+            'astNode' => $def,
             'serialize' => function() {
                 return false;
             },
@@ -555,7 +565,8 @@ class BuildSchema
         return [
             'name' => $def->name->value,
             'description' => $this->getDescription($def),
-            'fields' => function() use ($def) { return $this->makeInputValues($def->fields); }
+            'fields' => function() use ($def) { return $this->makeInputValues($def->fields); },
+            'astNode' => $def,
         ];
     }
 
diff --git a/tests/Type/DefinitionTest.php b/tests/Type/DefinitionTest.php
index 300fc72..86439e1 100644
--- a/tests/Type/DefinitionTest.php
+++ b/tests/Type/DefinitionTest.php
@@ -247,13 +247,14 @@ class DefinitionTest extends \PHPUnit_Framework_TestCase
             'description' => null,
             'deprecationReason' => 'Just because',
             'value' => 'foo',
+            'astNode' => null
         ], (array) $value);
 
         $this->assertEquals(true, $value->isDeprecated());
     }
 
     /**
-     * @it defines an enum type with a value of `null`
+     * @it defines an enum type with a value of `null` and `undefined`
      */
     public function testDefinesAnEnumTypeWithAValueOfNullAndUndefined()
     {
@@ -271,12 +272,14 @@ class DefinitionTest extends \PHPUnit_Framework_TestCase
                 'description' => null,
                 'deprecationReason' => null,
                 'value' => null,
+                'astNode' => null,
             ],
             [
                 'name' => 'UNDEFINED',
                 'description' => null,
                 'deprecationReason' => null,
                 'value' => null,
+                'astNode' => null,
             ],
         ];
 
diff --git a/tests/Utils/BuildSchemaTest.php b/tests/Utils/BuildSchemaTest.php
index 475983e..cbe1e7a 100644
--- a/tests/Utils/BuildSchemaTest.php
+++ b/tests/Utils/BuildSchemaTest.php
@@ -8,6 +8,9 @@ use GraphQL\Language\AST\InterfaceTypeDefinitionNode;
 use GraphQL\Language\AST\ObjectTypeDefinitionNode;
 use GraphQL\Language\AST\TypeNode;
 use GraphQL\Language\Parser;
+use GraphQL\Language\Printer;
+use GraphQL\Type\Definition\EnumType;
+use GraphQL\Type\Definition\ObjectType;
 use GraphQL\Utils\BuildSchema;
 use GraphQL\Utils\SchemaPrinter;
 
@@ -588,26 +591,19 @@ type Query {
         $ast = Parser::parse($body);
         $schema = BuildSchema::buildAST($ast);
 
-        $this->assertEquals($schema->getType('MyEnum')->getValues(), [
-            new EnumValueDefinition([
-                'name' => 'VALUE',
-                'description' => '',
-                'deprecationReason' => null,
-                'value' => 'VALUE'
-            ]),
-            new EnumValueDefinition([
-                'name' => 'OLD_VALUE',
-                'description' => '',
-                'deprecationReason' => 'No longer supported',
-                'value' => 'OLD_VALUE'
-            ]),
-            new EnumValueDefinition([
-                'name' => 'OTHER_VALUE',
-                'description' => '',
-                'deprecationReason' => 'Terrible reasons',
-                'value' => 'OTHER_VALUE'
-            ])
-        ]);
+        /** @var EnumType $myEnum */
+        $myEnum = $schema->getType('MyEnum');
+
+        $value = $myEnum->getValue('VALUE');
+        $this->assertFalse($value->isDeprecated());
+
+        $oldValue = $myEnum->getValue('OLD_VALUE');
+        $this->assertTrue($oldValue->isDeprecated());
+        $this->assertEquals('No longer supported', $oldValue->deprecationReason);
+
+        $otherValue = $myEnum->getValue('OTHER_VALUE');
+        $this->assertTrue($otherValue->isDeprecated());
+        $this->assertEquals('Terrible reasons', $otherValue->deprecationReason);
 
         $rootFields = $schema->getType('Query')->getFields();
         $this->assertEquals($rootFields['field1']->isDeprecated(), true);
@@ -617,6 +613,73 @@ type Query {
         $this->assertEquals($rootFields['field2']->deprecationReason, 'Because I said so');
     }
 
+    /**
+     * @it Correctly assign AST nodes
+     */
+    public function testCorrectlyAssignASTNodes()
+    {
+
+        $schema = BuildSchema::build('
+      schema {
+        query: Query
+      }
+
+      type Query {
+        testField(testArg: TestInput): TestUnion
+      }
+
+      input TestInput {
+        testInputField: TestEnum
+      }
+
+      enum TestEnum {
+        TEST_VALUE
+      }
+
+      union TestUnion = TestType
+
+      interface TestInterface {
+        interfaceField: String
+      }
+
+      type TestType implements TestInterface {
+        interfaceField: String
+      }
+
+      directive @test(arg: Int) on FIELD
+    ');
+        /** @var ObjectType $query */
+        $query = $schema->getType('Query');
+        $testInput = $schema->getType('TestInput');
+        $testEnum = $schema->getType('TestEnum');
+        $testUnion = $schema->getType('TestUnion');
+        $testInterface = $schema->getType('TestInterface');
+        $testType = $schema->getType('TestType');
+        $testDirective = $schema->getDirective('test');
+
+        $restoredIDL = SchemaPrinter::doPrint(BuildSchema::build(
+            Printer::doPrint($schema->getAstNode()) . "\n" .
+            Printer::doPrint($query->astNode) . "\n" .
+            Printer::doPrint($testInput->astNode) . "\n" .
+            Printer::doPrint($testEnum->astNode) . "\n" .
+            Printer::doPrint($testUnion->astNode) . "\n" .
+            Printer::doPrint($testInterface->astNode) . "\n" .
+            Printer::doPrint($testType->astNode) . "\n" .
+            Printer::doPrint($testDirective->astNode)
+        ));
+
+        $this->assertEquals($restoredIDL, SchemaPrinter::doPrint($schema));
+
+        $testField = $query->getField('testField');
+        $this->assertEquals('testField(testArg: TestInput): TestUnion', Printer::doPrint($testField->astNode));
+        $this->assertEquals('testArg: TestInput', Printer::doPrint($testField->args[0]->astNode));
+        $this->assertEquals('testInputField: TestEnum', Printer::doPrint($testInput->getField('testInputField')->astNode));
+        $this->assertEquals('TEST_VALUE', Printer::doPrint($testEnum->getValue('TEST_VALUE')->astNode));
+        $this->assertEquals('interfaceField: String', Printer::doPrint($testInterface->getField('interfaceField')->astNode));
+        $this->assertEquals('interfaceField: String', Printer::doPrint($testType->getField('interfaceField')->astNode));
+        $this->assertEquals('arg: Int', Printer::doPrint($testDirective->args[0]->astNode));
+    }
+
     // Describe: Failures
 
     /**
@@ -973,7 +1036,7 @@ interface Hello {
         $this->assertInstanceOf(\Closure::class, $defaultConfig['fields']);
         $this->assertInstanceOf(\Closure::class, $defaultConfig['interfaces']);
         $this->assertArrayHasKey('description', $defaultConfig);
-        $this->assertCount(4, $defaultConfig);
+        $this->assertCount(5, $defaultConfig);
         $this->assertEquals(array_keys($allNodesMap), ['Query', 'Color', 'Hello']);
         $this->assertEquals('My description of Query', $schema->getType('Query')->description);
 
@@ -985,12 +1048,12 @@ interface Hello {
             'description' => '',
             'deprecationReason' => ''
         ];
-        $this->assertEquals([
+        $this->assertArraySubset([
             'RED' => $enumValue,
             'GREEN' => $enumValue,
             'BLUE' => $enumValue,
         ], $defaultConfig['values']);
-        $this->assertCount(3, $defaultConfig);
+        $this->assertCount(4, $defaultConfig); // 3 + astNode
         $this->assertEquals(array_keys($allNodesMap), ['Query', 'Color', 'Hello']);
         $this->assertEquals('My description of Color', $schema->getType('Color')->description);
 
@@ -1000,7 +1063,7 @@ interface Hello {
         $this->assertInstanceOf(\Closure::class, $defaultConfig['fields']);
         $this->assertInstanceOf(\Closure::class, $defaultConfig['resolveType']);
         $this->assertArrayHasKey('description', $defaultConfig);
-        $this->assertCount(4, $defaultConfig);
+        $this->assertCount(5, $defaultConfig);
         $this->assertEquals(array_keys($allNodesMap), ['Query', 'Color', 'Hello']);
         $this->assertEquals('My description of Hello', $schema->getType('Hello')->description);
     }