diff --git a/core/lib/Drupal/Core/Entity/ContentEntityForm.php b/core/lib/Drupal/Core/Entity/ContentEntityForm.php
index f1a10ca..64374cf 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityForm.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityForm.php
@@ -135,4 +135,17 @@ public function setFormDisplay(EntityFormDisplayInterface $form_display, FormSta
     return $this;
   }
 
+  /**
+   * Updates the form language to reflect any change to the entity language.
+   *
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current state of the form.
+   */
+  protected function updateFormLangcode(FormStateInterface $form_state) {
+    // Update the form language as it might have changed.
+    if ($form_state->hasValue('langcode') && $this->isDefaultFormLangcode($form_state)) {
+      $form_state->set('langcode', $form_state->getValue('langcode'));
+    }
+  }
+
 }
diff --git a/core/lib/Drupal/Core/Entity/ContentEntityFormInterface.php b/core/lib/Drupal/Core/Entity/ContentEntityFormInterface.php
index 4d5cf4d..4f130dc 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityFormInterface.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityFormInterface.php
@@ -39,4 +39,26 @@ public function getFormDisplay(FormStateInterface $form_state);
    */
   public function setFormDisplay(EntityFormDisplayInterface $form_display, FormStateInterface $form_state);
 
+  /**
+   * Returns the code identifying the active form language.
+   *
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current state of the form.
+   *
+   * @return string
+   *   The form language code.
+   */
+  public function getFormLangcode(FormStateInterface $form_state);
+
+  /**
+   * Checks whether the current form language matches the entity one.
+   *
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current state of the form.
+   *
+   * @return boolean
+   *   Returns TRUE if the entity form language matches the entity one.
+   */
+  public function isDefaultFormLangcode(FormStateInterface $form_state);
+
 }
diff --git a/core/lib/Drupal/Core/Entity/EntityForm.php b/core/lib/Drupal/Core/Entity/EntityForm.php
index 407b9d7..0a46a2e 100644
--- a/core/lib/Drupal/Core/Entity/EntityForm.php
+++ b/core/lib/Drupal/Core/Entity/EntityForm.php
@@ -131,15 +131,6 @@ public function form(array $form, FormStateInterface $form_state) {
     // Add a process callback.
     $form['#process'][] = '::processForm';
 
-    if (!isset($form['langcode'])) {
-      // If the form did not specify otherwise, default to keeping the existing
-      // language of the entity or defaulting to the site default language for
-      // new entities.
-      $form['langcode'] = array(
-        '#type' => 'value',
-        '#value' => !$entity->isNew() ? $entity->language()->id : language_default()->id,
-      );
-    }
     return $form;
   }
 
@@ -232,7 +223,6 @@ protected function actions(array $form, FormStateInterface $form_state) {
    * {@inheritdoc}
    */
   public function validate(array $form, FormStateInterface $form_state) {
-    $this->updateFormLangcode($form_state);
     // @todo Remove this.
     // Execute legacy global validation handlers.
     $form_state->setValidateHandlers([]);
@@ -272,34 +262,6 @@ public function save(array $form, FormStateInterface $form_state) {
   /**
    * {@inheritdoc}
    */
-  public function getFormLangcode(FormStateInterface $form_state) {
-    return $this->entity->language()->id;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function isDefaultFormLangcode(FormStateInterface $form_state) {
-    // The entity is not translatable, this is always the default language.
-    return TRUE;
-  }
-
-  /**
-   * Updates the form language to reflect any change to the entity language.
-   *
-   * @param \Drupal\Core\Form\FormStateInterface $form_state
-   *   The current state of the form.
-   */
-  protected function updateFormLangcode(FormStateInterface $form_state) {
-    // Update the form language as it might have changed.
-    if ($form_state->hasValue('langcode') && $this->isDefaultFormLangcode($form_state)) {
-      $form_state->set('langcode', $form_state->getValue('langcode'));
-    }
-  }
-
-  /**
-   * {@inheritdoc}
-   */
   public function buildEntity(array $form, FormStateInterface $form_state) {
     $entity = clone $this->entity;
     $this->copyFormValuesToEntity($entity, $form, $form_state);
diff --git a/core/lib/Drupal/Core/Entity/EntityFormInterface.php b/core/lib/Drupal/Core/Entity/EntityFormInterface.php
index 2d63284..b8ecab1 100644
--- a/core/lib/Drupal/Core/Entity/EntityFormInterface.php
+++ b/core/lib/Drupal/Core/Entity/EntityFormInterface.php
@@ -18,28 +18,6 @@
 interface EntityFormInterface extends BaseFormIdInterface {
 
   /**
-   * Returns the code identifying the active form language.
-   *
-   * @param \Drupal\Core\Form\FormStateInterface $form_state
-   *   The current state of the form.
-   *
-   * @return string
-   *   The form language code.
-   */
-  public function getFormLangcode(FormStateInterface $form_state);
-
-  /**
-   * Checks whether the current form language matches the entity one.
-   *
-   * @param \Drupal\Core\Form\FormStateInterface $form_state
-   *   The current state of the form.
-   *
-   * @return boolean
-   *   Returns TRUE if the entity form language matches the entity one.
-   */
-  public function isDefaultFormLangcode(FormStateInterface $form_state);
-
-  /**
    * Sets the operation for this form.
    *
    * @param string $operation
diff --git a/core/modules/content_translation/content_translation.module b/core/modules/content_translation/content_translation.module
index 49e4b67..102c67a 100644
--- a/core/modules/content_translation/content_translation.module
+++ b/core/modules/content_translation/content_translation.module
@@ -7,7 +7,7 @@
 
 use Drupal\Core\Access\AccessResult;
 use Drupal\Core\Entity\ContentEntityInterface;
-use Drupal\Core\Entity\EntityFormInterface;
+use Drupal\Core\Entity\ContentEntityFormInterface;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Language\LanguageInterface;
@@ -364,7 +364,7 @@ function content_translation_access(EntityInterface $entity, $op) {
  */
 function content_translation_form_alter(array &$form, FormStateInterface $form_state) {
   $form_object = $form_state->getFormObject();
-  if (!($form_object instanceof EntityFormInterface)) {
+  if (!($form_object instanceof ContentEntityFormInterface)) {
     return;
   }
   $entity = $form_object->getEntity();