diff --git a/core/modules/config_translation/lib/Drupal/config_translation/ConfigFieldInstanceMapper.php b/core/modules/config_translation/lib/Drupal/config_translation/ConfigFieldInstanceMapper.php
index be497e4..44df444 100644
--- a/core/modules/config_translation/lib/Drupal/config_translation/ConfigFieldInstanceMapper.php
+++ b/core/modules/config_translation/lib/Drupal/config_translation/ConfigFieldInstanceMapper.php
@@ -19,14 +19,19 @@
 class ConfigFieldInstanceMapper extends ConfigEntityMapper {
 
   /**
+   * Loaded entity instance to help produce the translation interface.
+   *
+   * @var \Drupal\field\FieldInstanceInterface
+   */
+  protected $entity;
+
+  /**
    * {@inheritdoc}
    */
   public function getBaseRouteParameters() {
     $parameters = parent::getBaseRouteParameters();
     $base_entity_info = $this->entityManager->getDefinition($this->pluginDefinition['base_entity_type']);
-    // @todo Field instances have no method to return the bundle the instance is
-    //   attached to. See https://drupal.org/node/2134861
-    $parameters[$base_entity_info['bundle_entity_type']] = $this->entity->bundle;
+    $parameters[$base_entity_info['bundle_entity_type']] = $this->entity->targetBundle();
     return $parameters;
   }
 
diff --git a/core/modules/field/lib/Drupal/field/Entity/FieldInstance.php b/core/modules/field/lib/Drupal/field/Entity/FieldInstance.php
index 3af2671..bf0bfbf 100644
--- a/core/modules/field/lib/Drupal/field/Entity/FieldInstance.php
+++ b/core/modules/field/lib/Drupal/field/Entity/FieldInstance.php
@@ -588,6 +588,13 @@ public function allowBundleRename() {
     $this->bundle_rename_allowed = TRUE;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function targetBundle() {
+    return $this->bundle;
+  }
+
   /*
    * Implements the magic __sleep() method.
    *
diff --git a/core/modules/field/lib/Drupal/field/FieldInstanceInterface.php b/core/modules/field/lib/Drupal/field/FieldInstanceInterface.php
index aa06b83..f5df93b 100644
--- a/core/modules/field/lib/Drupal/field/FieldInstanceInterface.php
+++ b/core/modules/field/lib/Drupal/field/FieldInstanceInterface.php
@@ -32,4 +32,12 @@ public function getField();
    */
   public function allowBundleRename();
 
+  /**
+   * Returns the name of the bundle this field instance is attached to.
+   *
+   * @return string
+   *   The name of the bundle this field instance is attached to.
+   */
+  public function targetBundle();
+
 }