diff --git a/file_shadowbox/file_shadowbox.module b/file_shadowbox/file_shadowbox.module
index 7f48ec0..c785292 100644
--- a/file_shadowbox/file_shadowbox.module
+++ b/file_shadowbox/file_shadowbox.module
@@ -208,7 +208,9 @@ function file_shadowbox_field_formatter_view($entity_type, $entity, $field, $ins
       $gallery_id = $field['field_name'];
       break;
     case 'nid':
-      $gallery_id = "nid-{$entity->nid}";
+      $info = entity_get_info($entity_type);
+      $id = $info['entity keys']['id'];
+      $gallery_id = $entity_type . $entity->$id;
       break;
     case 'field_nid':
       $gallery_id = "nid-{$entity->nid}-{$field['field_name']}";
diff --git a/image_shadowbox/image_shadowbox.module b/image_shadowbox/image_shadowbox.module
index ed13827..f23848c 100644
--- a/image_shadowbox/image_shadowbox.module
+++ b/image_shadowbox/image_shadowbox.module
@@ -159,7 +159,9 @@ function image_shadowbox_field_formatter_view($entity_type, $entity, $field, $in
       $gallery_id = $field['field_name'];
       break;
     case 'nid':
-      $gallery_id = "nid-{$entity->nid}";
+      $info = entity_get_info($entity_type);
+      $id = $info['entity keys']['id'];
+      $gallery_id = $entity_type . $entity->$id;
       break;
     case 'field_nid':
       $gallery_id = "nid-{$entity->nid}-{$field['field_name']}";