diff --git a/src/Form/FormDataConstraintFinder.php b/src/Form/FormDataConstraintFinder.php
index <HASH>..<HASH> 100644
--- a/src/Form/FormDataConstraintFinder.php
+++ b/src/Form/FormDataConstraintFinder.php
@@ -35,9 +35,13 @@ class FormDataConstraintFinder
         if ($propertyPath->getLength() != 1) {
             throw new \RuntimeException('Not supported please submit a issue with the form that produces this error!');
         }
-
+        
         $property = $propertyPath->getElement(0);
         $constraintCollection = new ConstraintCollection();
+        if (!$metadata->hasPropertyMetadata($property)) {
+            return $constraintCollection;
+        }
+
         /** @var \Symfony\Component\Validator\Mapping\PropertyMetadata $propertyMetadata */
         foreach ($metadata->getPropertyMetadata($property) as $propertyMetadata) {
             $constraintCollection->addCollection(
Fix for #1

It makes sure that a notice given by `Symfony/Component/Validator/Mapping/ClassMetadata` will not happen.