diff --git a/Parser/FormTypeParser.php b/Parser/FormTypeParser.php
index a84ce26..d67d3f9 100644
--- a/Parser/FormTypeParser.php
+++ b/Parser/FormTypeParser.php
@@ -279,7 +279,15 @@ class FormTypeParser implements ParserInterface
 
     private function getTypeInstance($type)
     {
-        return unserialize(sprintf('O:%d:"%s":0:{}', strlen($type), $type));
+        $refl = new \ReflectionClass($type);
+        $constructor = $refl->getConstructor();
+
+        // this fallback may lead to runtime exception, but try hard to generate the docs
+        if ($constructor && $constructor->getNumberOfRequiredParameters() > 0) {
+            return $refl->newInstanceWithoutConstructor();
+        }
+
+        return $refl->newInstance();
     }
 
     private function createForm($item)
diff --git a/Tests/Fixtures/Form/RequireConstructionType.php b/Tests/Fixtures/Form/RequireConstructionType.php
new file mode 100644
index 0000000..4671495
--- /dev/null
+++ b/Tests/Fixtures/Form/RequireConstructionType.php
@@ -0,0 +1,57 @@
+<?php
+
+/*
+ * This file is part of the NelmioApiDocBundle.
+ *
+ * (c) Nelmio <hello@nelm.io>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Nelmio\ApiDocBundle\Tests\Fixtures\Form;
+
+use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\FormBuilderInterface;
+use Symfony\Component\OptionsResolver\OptionsResolverInterface;
+
+class RequireConstructionType extends AbstractType
+{
+    private $noThrow;
+
+    public function __construct($optionalArgs = null)
+    {
+        $this->noThrow = true;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function buildForm(FormBuilderInterface $builder, array $options)
+    {
+        if ($this->noThrow !== true)
+            throw new \RuntimeException(__CLASS__ . " require contruction");
+
+        $builder
+            ->add('a', null, array('description' => 'A nice description'))
+        ;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function setDefaultOptions(OptionsResolverInterface $resolver)
+    {
+        $resolver->setDefaults(array(
+            'data_class' => 'Nelmio\ApiDocBundle\Tests\Fixtures\Model\Test',
+        ));
+
+        return;
+    }
+
+
+    public function getName()
+    {
+        return 'require_construction_type';
+    }
+}
diff --git a/Tests/Formatter/SimpleFormatterTest.php b/Tests/Formatter/SimpleFormatterTest.php
index 38a21ce..6c85ff7 100644
--- a/Tests/Formatter/SimpleFormatterTest.php
+++ b/Tests/Formatter/SimpleFormatterTest.php
@@ -1080,17 +1080,26 @@ With multiple lines.',
                             'description' => '',
                             'sinceVersion' => null,
                             'untilVersion' => null,
+                            'actualType' => DataTypes::MODEL,
+                            'subType' => 'Nelmio\ApiDocBundle\Tests\Fixtures\Model\Test',
+                            'default' => null,
                             'children' => array(
                                 'a' => array(
                                     'dataType' => 'string',
                                     'format' => '{length: min: foo}, {not blank}',
                                     'required' => true,
-                                    'readonly' => null
+                                    'readonly' => null,
+                                    'actualType' => DataTypes::STRING,
+                                    'subType' => null,
+                                    'default' => 'nelmio',
                                 ),
                                 'b' => array(
                                     'dataType' => 'DateTime',
                                     'required' => null,
-                                    'readonly' => null
+                                    'readonly' => null,
+                                    'actualType' => DataTypes::DATETIME,
+                                    'subType' => null,
+                                    'default' => null,
                                 )
                             )
                         )
@@ -1207,17 +1216,26 @@ With multiple lines.',
                             'description' => '',
                             'sinceVersion' => null,
                             'untilVersion' => null,
+                            'actualType' => DataTypes::MODEL,
+                            'subType' => 'Nelmio\ApiDocBundle\Tests\Fixtures\Model\Test',
+                            'default' => null,
                             'children' => array(
                                 'a' => array(
                                     'dataType' => 'string',
                                     'format' => '{length: min: foo}, {not blank}',
                                     'required' => true,
-                                    'readonly' => null
+                                    'readonly' => null,
+                                    'actualType' => DataTypes::STRING,
+                                    'subType' => null,
+                                    'default' => 'nelmio',
                                 ),
                                 'b' => array(
                                     'dataType' => 'DateTime',
                                     'required' => null,
-                                    'readonly' => null
+                                    'readonly' => null,
+                                    'actualType' => DataTypes::DATETIME,
+                                    'subType' => null,
+                                    'default' => null,
                                 )
                             )
                         )
diff --git a/Tests/Parser/FormTypeParserTest.php b/Tests/Parser/FormTypeParserTest.php
index 08369f1..5a11485 100644
--- a/Tests/Parser/FormTypeParserTest.php
+++ b/Tests/Parser/FormTypeParserTest.php
@@ -473,7 +473,57 @@ class FormTypeParserTest extends \PHPUnit_Framework_TestCase
                             'readonly' => false,
                         ),
                 ),
-            )
+            ),
+            array(
+                array('class' => 'Nelmio\ApiDocBundle\Tests\Fixtures\Form\RequireConstructionType'),
+                array(
+                    'require_construction_type' => array(
+                        'dataType' => 'object (RequireConstructionType)',
+                        'required' => true,
+                        'description' => '',
+                        'readonly' => false,
+                        'default' => null,
+                        'actualType' => 'model',
+                        'subType' => 'Nelmio\ApiDocBundle\Tests\Fixtures\Form\RequireConstructionType',
+                        'children' => array(
+                            'a' => array(
+                                'dataType' => 'string',
+                                'actualType' => 'string',
+                                'subType' => null,
+                                'default' => null,
+                                'required' => true,
+                                'description' => 'A nice description',
+                                'readonly' => false,
+                            ),
+                        ),
+                    ),
+                ),
+            ),
+            array(
+                array('class' => 'Nelmio\ApiDocBundle\Tests\Fixtures\Form\DependencyType'),
+                array(
+                    'dependency_type' => array(
+                        'dataType' => 'object (DependencyType)',
+                        'required' => true,
+                        'description' => '',
+                        'readonly' => false,
+                        'default' => null,
+                        'actualType' => 'model',
+                        'subType' => 'Nelmio\ApiDocBundle\Tests\Fixtures\Form\DependencyType',
+                        'children' => array(
+                            'a' => array(
+                                'dataType' => 'string',
+                                'actualType' => 'string',
+                                'subType' => null,
+                                'default' => null,
+                                'required' => true,
+                                'description' => 'A nice description',
+                                'readonly' => false,
+                            ),
+                        ),
+                    ),
+                ),
+            ),
         );
     }
 }