diff --git a/src/TranslatableConfigPagesManager.php b/src/TranslatableConfigPagesManager.php
index c1779ec..11ea14f 100644
--- a/src/TranslatableConfigPagesManager.php
+++ b/src/TranslatableConfigPagesManager.php
@@ -36,7 +36,7 @@ class TranslatableConfigPagesManager implements TranslatableConfigPagesManagerIn
   /**
    * {@inheritdoc}
    */
-  public function loadConfig(string $bundle, LanguageInterface $language = NULL): ?TranslatableConfigPages {
+  public function loadConfig(string $bundle, ?LanguageInterface $language = NULL): ?TranslatableConfigPages {
     $entity = NULL;
 
     try {
@@ -64,7 +64,7 @@ class TranslatableConfigPagesManager implements TranslatableConfigPagesManagerIn
   /**
    * {@inheritdoc}
    */
-  public function loadConfigFieldValue(string $bundle, string $field, LanguageInterface $language = NULL): mixed {
+  public function loadConfigFieldValue(string $bundle, string $field, ?LanguageInterface $language = NULL): mixed {
     $entity = $this->loadConfig($bundle, $language);
 
     if ($entity && $entity->hasField($field)) {
diff --git a/src/TranslatableConfigPagesManagerInterface.php b/src/TranslatableConfigPagesManagerInterface.php
index 5526a7f..7329646 100644
--- a/src/TranslatableConfigPagesManagerInterface.php
+++ b/src/TranslatableConfigPagesManagerInterface.php
@@ -23,7 +23,7 @@ interface TranslatableConfigPagesManagerInterface {
    * @return null|\Drupal\translatable_config_pages\Entity\TranslatableConfigPages
    *   Loaded config page.
    */
-  public function loadConfig(string $bundle, LanguageInterface $language = NULL): ?TranslatableConfigPages;
+  public function loadConfig(string $bundle, ?LanguageInterface $language = NULL): ?TranslatableConfigPages;
 
   /**
    * Loads config page field value by bundle and language.
@@ -38,6 +38,6 @@ interface TranslatableConfigPagesManagerInterface {
    * @return mixed
    *   Loaded field value.
    */
-  public function loadConfigFieldValue(string $bundle, string $field, LanguageInterface $language = NULL): mixed;
+  public function loadConfigFieldValue(string $bundle, string $field, ?LanguageInterface $language = NULL): mixed;
 
 }