diff --git a/core/lib/Drupal/Core/Entity/EntityManager.php b/core/lib/Drupal/Core/Entity/EntityManager.php
index e8987e2..3e34150 100644
--- a/core/lib/Drupal/Core/Entity/EntityManager.php
+++ b/core/lib/Drupal/Core/Entity/EntityManager.php
@@ -438,9 +438,7 @@ public function getAdminRouteInfo($entity_type, $bundle) {
   /**
    * Gets an array of content entity field definitions.
    *
-   * If a bundle is passed, fields specific to this bundle are included. Entity
-   * fields are always multi-valued, so 'list' is TRUE for each returned field
-   * definition.
+   * If a bundle is passed, fields specific to this bundle are included.
    *
    * @param string $entity_type
    *   The entity type to get field definitions for. Only entity types that
@@ -492,8 +490,7 @@ public function getFieldDefinitions($entity_type, $bundle = NULL) {
         $hooks = array('entity_field_info', $entity_type . '_field_info');
         $this->moduleHandler->alter($hooks, $this->entityFieldInfo[$entity_type], $entity_type);
 
-        // Enforce field definitions to be objects, and fields to be
-        // untranslatable by default.
+        // Enforce field definitions to be objects.
         $entity_info = $this->getDefinition($entity_type);
         $keys = array_intersect_key(array_filter($entity_info['entity_keys']), array_flip(array('id', 'revision', 'uuid', 'bundle')));
         $untranslatable_fields = array_flip(array('langcode') + $keys);
@@ -510,9 +507,6 @@ public function getFieldDefinitions($entity_type, $bundle = NULL) {
             if (isset($untranslatable_fields[$field_name]) && $definition->isFieldTranslatable()) {
               throw new \LogicException(format_string('The @field field cannot be translatable.', array('@field' => $definition->getFieldLabel())));
             }
-            if ($definition->isFieldTranslatable()) {
-              $definition->setTranslatable(FALSE);
-            }
           }
         }
 
diff --git a/core/lib/Drupal/Core/Entity/Field/FieldDefinition.php b/core/lib/Drupal/Core/Entity/Field/FieldDefinition.php
index dd9ef34..b2cf431 100644
--- a/core/lib/Drupal/Core/Entity/Field/FieldDefinition.php
+++ b/core/lib/Drupal/Core/Entity/Field/FieldDefinition.php
@@ -307,6 +307,9 @@ public static function createFromOldStyleDefinition(array $definition) {
     if (isset($definition['constraints'])) {
       $item_definition->setConstraints($definition['constraints']);
     }
+    if (isset($definition['translatable']) && $definition['translatable']) {
+      $field_definition->setTranslatable($definition['translatable']);
+    }
     $field_definition->setItemDefinition($item_definition);
     return $field_definition;
   }
diff --git a/core/modules/content_translation/content_translation.admin.inc b/core/modules/content_translation/content_translation.admin.inc
index b2a83b1..337efd4 100644
--- a/core/modules/content_translation/content_translation.admin.inc
+++ b/core/modules/content_translation/content_translation.admin.inc
@@ -102,7 +102,7 @@ function _content_translation_form_language_content_settings_form_alter(array &$
             // translation.
             // @todo Remove this special casing as soon as configurable and
             //   base field definitions are "unified".
-            if (!empty($definition['configurable']) && ($field = FieldService::fieldInfo()->getField($entity_type, $field_name))) {
+            if ($definition->isFieldConfigurable() && ($field = FieldService::fieldInfo()->getField($entity_type, $field_name))) {
               $instance = FieldService::fieldInfo()->getInstance($entity_type, $bundle, $field_name);
               $form['settings'][$entity_type][$bundle]['fields'][$field_name] = array(
                 '#label' => $instance->getFieldLabel(),
diff --git a/core/modules/content_translation/content_translation.module b/core/modules/content_translation/content_translation.module
index d67c7f9..f92e559 100644
--- a/core/modules/content_translation/content_translation.module
+++ b/core/modules/content_translation/content_translation.module
@@ -145,8 +145,15 @@ function content_translation_entity_field_info_alter(&$info, $entity_type) {
     foreach ($fields as $name => $translatable) {
       foreach ($keys as $key) {
         if (isset($info[$key][$name])) {
-          $info[$key][$name]['translatable'] = (bool) $translatable;
-          break;
+          $translatable = (bool) $translatable;
+          // @todo: Remove array check after all base fields have been
+          // converted to object.
+          if (is_array($info[$key][$name])) {
+            $info[$key][$name]['translatable'] = $translatable;
+          }
+          elseif (is_object($info[$key][$name])) {
+            $info[$key][$name]->setTranslatable($translatable);
+          }
         }
       }
     }
diff --git a/core/modules/field/lib/Drupal/field/Entity/Field.php b/core/modules/field/lib/Drupal/field/Entity/Field.php
index da6129f..150311c 100644
--- a/core/modules/field/lib/Drupal/field/Entity/Field.php
+++ b/core/modules/field/lib/Drupal/field/Entity/Field.php
@@ -578,6 +578,20 @@ public function isFieldTranslatable() {
   }
 
   /**
+   * Sets whether the field is translatable.
+   *
+   * @param bool $translatable
+   *   Whether the field is translatable.
+   *
+   * @return \Drupal\field\Entity\Field
+   *   The object itself for chaining.
+   */
+  public function setTranslatable($translatable) {
+    $this->translatable = $translatable;
+    return $this;
+  }
+
+  /**
    * {@inheritdoc}
    */
   public function getFieldLabel() {