diff --git a/src/Form/Manipulator/DoctrineORMManipulator.php b/src/Form/Manipulator/DoctrineORMManipulator.php
index 2554fd8..8cbfe23 100644
--- a/src/Form/Manipulator/DoctrineORMManipulator.php
+++ b/src/Form/Manipulator/DoctrineORMManipulator.php
@@ -31,21 +31,27 @@ public function __construct(DoctrineORMInfo $doctrineORMInfo, array $globalExclu
 
     public function getFieldsConfig(FormInterface $form): array
     {
-        $class = $this->getDataClass($form);
         $formOptions = $form->getConfig()->getOptions();
-
-        // Filtering to remove excludedFields
-        $objectFieldsConfig = $this->doctrineORMInfo->getFieldsConfig($class);
-        $validObjectFieldsConfig = $this->filteringValidObjectFields($objectFieldsConfig, $formOptions['excluded_fields']);
-
-        if (empty($formOptions['fields'])) {
-            return $validObjectFieldsConfig;
+        if (array_key_exists('mapped', $formOptions) && false !== $formOptions) {
+            $class = null;
+            $validObjectFieldsConfig = [];
+        } else {
+            $class = $this->getDataClass($form);
+
+            // Filtering to remove excludedFields
+            $objectFieldsConfig = $this->doctrineORMInfo->getFieldsConfig($class);
+            $validObjectFieldsConfig = $this->filteringValidObjectFields($objectFieldsConfig, $formOptions['excluded_fields']);
+
+            if (empty($formOptions['fields'])) {
+                return $validObjectFieldsConfig;
+            }
         }
 
         $fields = [];
-
         foreach ($formOptions['fields'] as $formFieldName => $formFieldConfig) {
-            $this->checkFieldIsValid($formFieldName, $formFieldConfig, $validObjectFieldsConfig, $class);
+            if ($class) {
+                $this->checkFieldIsValid($formFieldName, $formFieldConfig, $validObjectFieldsConfig, $class);
+            }
 
             if (null === $formFieldConfig) {
                 continue;
diff --git a/src/Form/Type/AutoFormType.php b/src/Form/Type/AutoFormType.php
index e48a0f6..67da5e0 100644
--- a/src/Form/Type/AutoFormType.php
+++ b/src/Form/Type/AutoFormType.php
@@ -40,13 +40,5 @@ public function configureOptions(OptionsResolver $resolver): void
             'fields' => [],
             'excluded_fields' => [],
         ]);
-
-        $resolver->setNormalizer('data_class', function (Options $options, $value): string {
-            if (empty($value)) {
-                throw new \RuntimeException('Missing "data_class" option of "AutoFormType".');
-            }
-
-            return $value;
-        });
     }
 }