--- /dev/null
+<?php
+
+namespace Drupal\taxonomy;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\content_translation\ContentTranslationHandler;
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Defines the translation handler for terms.
+ */
+class TermTranslationHandler extends ContentTranslationHandler {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function entityFormAlter(array &$form, FormStateInterface $form_state, EntityInterface $entity) {
+ parent::entityFormAlter($form, $form_state, $entity);
+ $form['actions']['submit']['#submit'][] = [$this, 'entityFormSave'];
+ }
+
+ /**
+ * Form submission handler for TermTranslationHandler::entityFormAlter().
+ *
+ * This handles the save action.
+ *
+ * @see \Drupal\Core\Entity\EntityForm::build()
+ */
+ public function entityFormSave(array $form, FormStateInterface $form_state) {
+ if ($this->getSourceLangcode($form_state)) {
+ $entity = $form_state->getFormObject()->getEntity();
+ // We need a redirect here, otherwise we would get an access denied page,
+ // since the current URL would be preserved and we would try to add a
+ // translation for a language that already has a translation.
+ $form_state->setRedirectUrl($entity->urlInfo('edit-form'));
+ }
+ }
+
+}