diff --git a/entity_metadata/modules/field.info.inc b/entity_metadata/modules/field.info.inc
index a28099e..94f3597 100644
--- a/entity_metadata/modules/field.info.inc
+++ b/entity_metadata/modules/field.info.inc
@@ -95,7 +95,9 @@ function entity_metadata_field_term_reference_callback(&$info, $entity_type, $fi
   $property = &$info[$entity_type]['bundles'][$instance['bundle']]['properties'][$field['field_name']];
   if (count($field['settings']['allowed_values']) == 1) {
     $settings = reset($field['settings']['allowed_values']);
-    $property['bundle'] = $settings['vocabulary'];
+    if (!empty($settings['vocabulary'])) {
+      $property['bundle'] = $settings['vocabulary'];
+    }
   }
   $property['options list'] = 'entity_metadata_field_options_list';
   unset($property['query callback']);