diff --git a/core/lib/Drupal/Core/Form/ConfigFormBase.php b/core/lib/Drupal/Core/Form/ConfigFormBase.php
index 9781f34f99..cc0b002d84 100644
--- a/core/lib/Drupal/Core/Form/ConfigFormBase.php
+++ b/core/lib/Drupal/Core/Form/ConfigFormBase.php
@@ -53,7 +53,7 @@ public function buildForm(array $form, FormStateInterface $form_state) {
    * {@inheritdoc}
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
-    $this->messenger->addStatus($this->t('The configuration options have been saved.'));
+    $this->messenger()->addStatus($this->t('The configuration options have been saved.'));
   }
 
 }
diff --git a/core/lib/Drupal/Core/Form/FormErrorHandler.php b/core/lib/Drupal/Core/Form/FormErrorHandler.php
index 88ec061aa4..511fe7bc4d 100644
--- a/core/lib/Drupal/Core/Form/FormErrorHandler.php
+++ b/core/lib/Drupal/Core/Form/FormErrorHandler.php
@@ -41,7 +41,7 @@ protected function displayErrorMessages(array $form, FormStateInterface $form_st
 
     // Loop through all form errors and set an error message.
     foreach ($errors as $error) {
-      $this->messenger->addError($error);
+      $this->messenger()->addError($error);
     }
   }