Index: modules/importexportapi/definitions/importexportapi_system.inc
===================================================================
--- modules/importexportapi/definitions/importexportapi_system.inc	(revision 233)
+++ modules/importexportapi/definitions/importexportapi_system.inc	(working copy)
@@ -78,13 +78,15 @@
   $def['file_revisions']['fid'] = array(
     '#type' => 'int',
     '#title' => t('File ID'),
-    '#reference_entity' => 'file'
+    '#reference_entity' => 'file',
+    '#key_component' => TRUE
   );
   $def['file_revisions']['vid'] = array(
     '#type' => 'int',
     '#title' => t('Node revision ID'),
     '#reference_entity' => 'node',
-    '#reference_field' => array('revisions', 'vid')
+    '#reference_field' => array('revisions', 'vid'),
+    '#key_component' => TRUE
   );
   $def['file_revisions']['description'] = array(
     '#title' => t('Description')