diff --git a/core/modules/translation_entity/translation_entity.install b/core/modules/translation_entity/translation_entity.install
index ff7a7d7..4e7cdd3 100644
--- a/core/modules/translation_entity/translation_entity.install
+++ b/core/modules/translation_entity/translation_entity.install
@@ -55,5 +55,6 @@ function translation_entity_schema() {
  * Implements hook_install().
  */
 function translation_entity_install() {
+  require_once DRUPAL_ROOT . '/core/includes/language.inc';
   language_negotiation_set(LANGUAGE_TYPE_CONTENT, array(LANGUAGE_NEGOTIATION_URL => 0));
 }