diff --git a/Service/Validator/AbstractImageValidator.php b/Service/Validator/AbstractImageValidator.php
index fce0fed..a6fdf3b 100644
--- a/Service/Validator/AbstractImageValidator.php
+++ b/Service/Validator/AbstractImageValidator.php
@@ -10,7 +10,7 @@
 
 namespace Jb\Bundle\FileUploaderBundle\Service\Validator;
 
-use Symfony\Component\OptionsResolver\OptionsResolverInterface;
+use Symfony\Component\OptionsResolver\OptionsResolver;
 use Jb\Bundle\FileUploaderBundle\Exception\ValidationException;
 
 /**
@@ -23,9 +23,9 @@ abstract class AbstractImageValidator extends AbstractValidator
     /**
      * {@inheritdoc}
      */
-    protected function configureOptions(OptionsResolverInterface $resolver)
+    protected function configureOptions(OptionsResolver $resolver)
     {
-        $resolver->setOptional(array(
+        $resolver->setDefined(array(
             'MinWidth',
             'MaxWidth',
             'MinHeight',
diff --git a/Service/Validator/AbstractValidator.php b/Service/Validator/AbstractValidator.php
index 296433b..305cd83 100644
--- a/Service/Validator/AbstractValidator.php
+++ b/Service/Validator/AbstractValidator.php
@@ -11,7 +11,6 @@
 namespace Jb\Bundle\FileUploaderBundle\Service\Validator;
 
 use Symfony\Component\OptionsResolver\OptionsResolver;
-use Symfony\Component\OptionsResolver\OptionsResolverInterface;
 
 /**
  * AbstractValidator
@@ -23,9 +22,9 @@ abstract class AbstractValidator
     /**
      * Configure the validator
      *
-     * @param OptionsResolverInterface $resolver
+     * @param OptionsResolver $resolver
      */
-    protected function configureOptions(OptionsResolverInterface $resolver)
+    protected function configureOptions(OptionsResolver $resolver)
     {
     }
 
@@ -51,6 +50,7 @@ public function applyValidator($value, array $configuration)
      * Extract the value used in the validator
      *
      * @param mixed $value
+     * @return mixed|string
      */
     protected function formatValue($value)
     {