diff --git a/core/modules/forum/forum.views.inc b/core/modules/forum/forum.views.inc
index 06d56e7..21dcc7f 100644
--- a/core/modules/forum/forum.views.inc
+++ b/core/modules/forum/forum.views.inc
@@ -71,6 +71,9 @@ function forum_views_data() {
       'numeric' => TRUE,
       'skip base' => 'taxonomy_term_data',
     ),
+    'field' => array(
+      'id' => 'numeric',
+    ),
     'filter' => array(
       'title' => t('Has taxonomy term'),
       'id' => 'taxonomy_index_tid',