diff --git a/core/lib/Drupal/Core/Entity/DatabaseStorageController.php b/core/lib/Drupal/Core/Entity/DatabaseStorageController.php
index a3cd9df..69265c2 100644
--- a/core/lib/Drupal/Core/Entity/DatabaseStorageController.php
+++ b/core/lib/Drupal/Core/Entity/DatabaseStorageController.php
@@ -583,13 +583,18 @@ public function getFieldDefinitions(array $constraints) {
         $hooks = array('entity_field_info', $this->entityType . '_property_info');
         drupal_alter($hooks, $this->entityFieldInfo, $this->entityType);
 
-        // Enforce fields to be multiple by default.
-        foreach ($this->entityFieldInfo['definitions'] as &$definition) {
-          $definition['list'] = TRUE;
-        }
-        foreach ($this->entityFieldInfo['optional'] as &$definition) {
-          $definition['list'] = TRUE;
+        // Enforce fields to be multiple and untranslatable by default.
+        $base_fields = array_flip(array_filter(array($this->idKey, $this->revisionKey, $this->bundleKey, $this->uuidKey, 'langcode')));
+        foreach (array('definitions', 'optional') as $key) {
+          foreach ($this->entityFieldInfo[$key] as $name => &$definition) {
+            $definition['list'] = TRUE;
+            // Ensure base fields are never made translatable.
+            if (isset($base_fields[$name]) || !isset($definition['translatable'])) {
+              $definition['translatable'] = FALSE;
+            }
+          }
         }
+
         cache()->set($cid, $this->entityFieldInfo, CacheBackendInterface::CACHE_PERMANENT, array('entity_info' => TRUE));
       }
     }
diff --git a/core/modules/translation_entity/translation_entity.admin.inc b/core/modules/translation_entity/translation_entity.admin.inc
index 01e9368..785e4ad 100644
--- a/core/modules/translation_entity/translation_entity.admin.inc
+++ b/core/modules/translation_entity/translation_entity.admin.inc
@@ -76,6 +76,8 @@ function _translation_entity_form_language_content_settings_form_alter(array &$f
   $dependent_options_settings = array();
   foreach ($form['#labels'] as $entity_type => $label) {
     $entity_info = entity_get_info($entity_type);
+    $controller = Drupal::entityManager()->getStorageController($entity_type);
+
     foreach (entity_get_bundles($entity_type) as $bundle => $bundle_info) {
       // Here we do not want the widget to be altered and hold also the "Enable
       // translation" checkbox, which would be redundant. Hence we add this key
@@ -85,35 +87,55 @@ function _translation_entity_form_language_content_settings_form_alter(array &$f
       // Only show the checkbox to enable translation if the bundles in the
       // entity might have fields and if there are fields to translate.
       if (!empty($entity_info['fieldable'])) {
-        $fields = field_info_instances($entity_type, $bundle);
+        $fields = $controller->getFieldDefinitions(array('EntityType' => $entity_type, 'Bundle' => $bundle));
+
         if ($fields) {
           $form['settings'][$entity_type][$bundle]['translatable'] = array(
             '#type' => 'checkbox',
             '#default_value' => translation_entity_enabled($entity_type, $bundle),
           );
 
-          // @todo Exploit field definitions once all core entities and field
-          // types are migrated to the Entity Field API.
-          foreach ($fields as $field_name => $instance) {
-            $field = field_info_field($field_name);
-            $form['settings'][$entity_type][$bundle]['fields'][$field_name] = array(
-              '#label' => $instance['label'],
-              '#type' => 'checkbox',
-              '#default_value' => $field['translatable'],
-            );
-            $column_element = translation_entity_field_sync_widget($field, $instance);
-            if ($column_element) {
-              $form['settings'][$entity_type][$bundle]['columns'][$field_name] = $column_element;
-
-              if (isset($column_element['#options']['file'])) {
-                $dependent_options_settings["settings[{$entity_type}][{$bundle}][columns][{$field_name}]"] = array('file');
+          $field_settings = translation_entity_get_config($entity_type, $bundle, 'fields');
+          foreach ($fields as $field_name => $definition) {
+            $translatable = !empty($field_settings[$field_name]);
+
+            // We special case Field API fields as they always natively support
+            // translation.
+            if (!empty($definition['configurable']) && ($field = field_info_field($field_name))) {
+              $instance = field_info_instance($entity_type, $field_name, $bundle);
+              $form['settings'][$entity_type][$bundle]['fields'][$field_name] = array(
+                '#label' => $instance['label'],
+                '#type' => 'checkbox',
+                '#default_value' => $translatable,
+              );
+
+              $column_element = translation_entity_field_sync_widget($field, $instance);
+              if ($column_element) {
+                $form['settings'][$entity_type][$bundle]['columns'][$field_name] = $column_element;
+
+                // @todo This should not concern only files.
+                if (isset($column_element['#options']['file'])) {
+                  $dependent_options_settings["settings[{$entity_type}][{$bundle}][columns][{$field_name}]"] = array('file');
+                }
               }
             }
+            // Instead we need to rely on field definitions to determine whether
+            // they support translation. Whether they are actually enabled is
+            // determined through our settings. As a consequence only fields
+            // that support translation can be enabled or disabled.
+            elseif (isset($field_settings[$field_name]) || !empty($definition['translatable'])) {
+              $form['settings'][$entity_type][$bundle]['fields'][$field_name] = array(
+                '#label' => $definition['label'],
+                '#type' => 'checkbox',
+                '#default_value' => $translatable,
+              );
+            }
           }
         }
       }
     }
   }
+
   $settings = array('dependent_selectors' => $dependent_options_settings);
   $form['#attached']['js'][] = array('data' => array('translationEntityDependentOptions' => $settings), 'type' => 'setting');
   $form['#validate'][] = 'translation_entity_form_language_content_settings_validate';
@@ -326,11 +348,11 @@ function _translation_entity_update_field_translatability($settings) {
         foreach ($bundle_settings['fields'] as $field_name => $translatable) {
           // If a field is enabled for translation for at least one instance we
           // need to mark it as translatable.
-          $fields[$field_name] = $translatable || !empty($fields[$field_name]);
+          if (field_info_field($field_name)) {
+            $fields[$field_name] = $translatable || !empty($fields[$field_name]);
+          }
         }
       }
-      // @todo Store non-configurable field settings to be able to alter their
-      //   definition afterwards.
     }
   }
 
diff --git a/core/modules/translation_entity/translation_entity.module b/core/modules/translation_entity/translation_entity.module
index dec0460..275e6a7 100644
--- a/core/modules/translation_entity/translation_entity.module
+++ b/core/modules/translation_entity/translation_entity.module
@@ -125,6 +125,33 @@ function translation_entity_entity_bundle_info_alter(&$bundles) {
 }
 
 /**
+ * Implements hook_entity_field_info_alter().
+ */
+function translation_entity_entity_field_info_alter(&$info, $entity_type) {
+  $translation_settings = config('translation_entity.settings')->get($entity_type);
+
+  if ($translation_settings) {
+    // Currently field translatability is defined per-field but we may want to
+    // make it per-instance instead, so leaving the possibility open for further
+    // easier refactoring.
+    $fields = array();
+    foreach ($translation_settings as $bundle => $settings) {
+      $fields += !empty($settings['translation_entity']['fields']) ? $settings['translation_entity']['fields'] : array();
+    }
+
+    $keys = array('definitions', 'optional');
+    foreach ($fields as $name => $translatable) {
+      foreach ($keys as $key) {
+        if (isset($info[$key][$name])) {
+          $info[$key][$name]['translatable'] = (bool) $translatable;
+          break;
+        }
+      }
+    }
+  }
+}
+
+/**
  * Implements hook_menu().
  */
 function translation_entity_menu() {
@@ -1015,6 +1042,11 @@ function translation_entity_save_settings($settings) {
         // Store whether a bundle has translation enabled or not.
         translation_entity_set_config($entity_type, $bundle, 'enabled', $bundle_settings['translatable']);
 
+        // Store whether fields are translatable or not.
+        if (!empty($bundle_settings['fields'])) {
+          translation_entity_set_config($entity_type, $bundle, 'fields', $bundle_settings['fields']);
+        }
+
         // Store whether fields have translation enabled or not.
         if (!empty($bundle_settings['columns'])) {
           foreach ($bundle_settings['columns'] as $field_name => $column_settings) {