diff --git a/.gitignore b/.gitignore
index a7c4e1c..5c2d360 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 composer.lock
 coverage/
 .phpunit.result.cache
+.idea/
diff --git a/composer.json b/composer.json
index 57f9e7c..a6551b7 100644
--- a/composer.json
+++ b/composer.json
@@ -21,10 +21,10 @@
     },
     "require": {
         "php": "^7.4|^8.0",
-        "symfony/form": "^5.4|^6.0",
-        "symfony/translation": "^5.4|^6.0",
-        "symfony/serializer": "^5.4|^6.0",
-        "symfony/validator": "^5.4|^6.0"
+        "symfony/form": "^5.4|^6.0|^7.0",
+        "symfony/translation": "^5.4|^6.0|^7.0",
+        "symfony/serializer": "^5.4|^6.0|^7.0",
+        "symfony/validator": "^5.4|^6.0|^7.0"
     },
     "require-dev": {
         "dealerdirect/phpcodesniffer-composer-installer": "^v0.7.2",
diff --git a/src/Limenius/Liform/Form/Extension/AddLiformExtension.php b/src/Limenius/Liform/Form/Extension/AddLiformExtension.php
index d59e40f..9f804a4 100644
--- a/src/Limenius/Liform/Form/Extension/AddLiformExtension.php
+++ b/src/Limenius/Liform/Form/Extension/AddLiformExtension.php
@@ -47,7 +47,7 @@ public static function getExtendedTypes(): iterable
      *
      * @param OptionsResolver $resolver
      */
-    public function configureOptions(OptionsResolver $resolver)
+    public function configureOptions(OptionsResolver $resolver): void
     {
         $resolver->setDefined(['liform']);
     }
diff --git a/src/Limenius/Liform/Serializer/Normalizer/FormErrorNormalizer.php b/src/Limenius/Liform/Serializer/Normalizer/FormErrorNormalizer.php
index 8e8075d..e9db9ab 100644
--- a/src/Limenius/Liform/Serializer/Normalizer/FormErrorNormalizer.php
+++ b/src/Limenius/Liform/Serializer/Normalizer/FormErrorNormalizer.php
@@ -39,7 +39,7 @@ public function __construct(TranslatorInterface $translator)
     /**
      * {@inheritdoc}
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize(mixed $object, ?string $format = null, array $context = []): float|array|\ArrayObject|bool|int|string|null
     {
         return [
             'code' => isset($context['status_code']) ? $context['status_code'] : null,
@@ -51,11 +51,19 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization(mixed $data, ?string $format = null, array $context = []): bool
     {
         return $data instanceof FormInterface && $data->isSubmitted() && !$data->isValid();
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function getSupportedTypes(?string $format): array
+    {
+        return ['object' => true];
+    }
+
     /**
      * This code has been taken from JMSSerializer.
      *
diff --git a/src/Limenius/Liform/Serializer/Normalizer/InitialValuesNormalizer.php b/src/Limenius/Liform/Serializer/Normalizer/InitialValuesNormalizer.php
index cd143b5..2b76461 100644
--- a/src/Limenius/Liform/Serializer/Normalizer/InitialValuesNormalizer.php
+++ b/src/Limenius/Liform/Serializer/Normalizer/InitialValuesNormalizer.php
@@ -27,25 +27,34 @@ class InitialValuesNormalizer implements NormalizerInterface
     /**
      * {@inheritdoc}
      */
-    public function normalize($form, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): float|array|\ArrayObject|bool|int|string|null
     {
-        $formView = $form->createView();
+        $formView = $object->createView();
 
-        return $this->getValues($form, $formView);
+        return $this->getValues($object, $formView);
     }
 
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization(mixed $data, ?string $format = null, array $context = []): bool
     {
         return $data instanceof Form;
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function getSupportedTypes(?string $format): array
+    {
+        return ['object' => true];
+    }
+
     /**
      * Gets the values of the form
-     * @param Form|FormInterface     $form
-     * @param FormView               $formView
+     *
+     * @param Form|FormInterface $form
+     * @param FormView $formView
      *
      * @return mixed
      */
@@ -62,7 +71,7 @@ private function getValues(FormInterface $form, FormView $formView)
                 return $this->normalizeExpandedChoice($formView);
             }
             // Force serialization as {} instead of []
-            $data = (object) array();
+            $data = (object) [];
             foreach ($formView->children as $name => $child) {
                 // Avoid unknown field error when csrf_protection is true
                 // CSRF token should be extracted another way
@@ -85,13 +94,14 @@ private function getValues(FormInterface $form, FormView $formView)
 
     /**
      * Normalize when choice is multiple
+     *
      * @param FormView $formView
      *
      * @return array
      */
     private function normalizeMultipleExpandedChoice(FormView $formView)
     {
-        $data = array();
+        $data = [];
         foreach ($formView->children as $name => $child) {
             if ($child->vars['checked']) {
                 $data[] = $child->vars['value'];
@@ -103,6 +113,7 @@ private function normalizeMultipleExpandedChoice(FormView $formView)
 
     /**
      * Normalize when choice is expanded
+     *
      * @param FormView $formView
      *
      * @return mixed