diff --git a/core/modules/taxonomy/taxonomy.install b/core/modules/taxonomy/taxonomy.install
index ae6e006..55c225f 100644
--- a/core/modules/taxonomy/taxonomy.install
+++ b/core/modules/taxonomy/taxonomy.install
@@ -352,33 +352,36 @@ function taxonomy_update_8006() {
  * Update taxonomy_term_reference field tables to use target_id instead of tid.
  */
 function taxonomy_update_8007() {
-  // @todo Switch to the update-safe version of this function when we have one.
-  if (!$fields = field_read_fields(array('type' => 'taxonomy_term_reference'), array('include_inactive' => 1))) {
-    return;
-  }
+  foreach (config_get_storage_names_with_prefix('field.field.') as $config_name) {
+    $field_config = config($config_name);
+    // Only update taxonomy reference fields that use the default SQL storage.
+    if ($field_config->get('type') == 'taxonomy_term_reference' && $field_config->get('storage.type') == 'field_sql_storage') {
+      $field_id = $field_config->get('id');
+      $field = array(
+        // _field_sql_storage_tablename() still relies on the 'field_name'
+        // property.
+        'field_name' => $field_id,
+        'deleted' => FALSE,
+      );
 
-  foreach ($fields as $field_name => $field) {
-    if ($field['storage']['type'] != 'field_sql_storage') {
-      // Field doesn't use SQL storage, we cannot modify the schema.
-      continue;
-    }
+      $tables = array(
+        _field_sql_storage_tablename($field),
+        _field_sql_storage_revision_tablename($field),
+      );
 
-    $tables = array(
-      _field_sql_storage_tablename($field),
-      _field_sql_storage_revision_tablename($field),
-    );
+      foreach ($tables as $table_name) {
+        db_change_field($table_name, $field_id . '_tid', $field_id . '_target_id', array(
+          'description' => 'The ID of the target entity.',
+          'type' => 'int',
+          'unsigned' => TRUE,
+          'not null' => FALSE,
+        ));
 
-    foreach ($tables as $table_name) {
-      db_change_field($table_name, $field_name . '_tid', $field_name . '_target_id', array(
-        'description' => 'The ID of the target entity.',
-        'type' => 'int',
-        'unsigned' => TRUE,
-        'not null' => FALSE,
-      ));
+        // Change the index.
+        db_drop_index($table_name, $field_id . '_tid');
+        db_add_index($table_name, $field_id . '_target_id', array($field_id . '_target_id'));
+      }
 
-      // Change the index.
-      db_drop_index($table_name, $field_name . '_tid');
-      db_add_index($table_name, $field_name . '_target_id', array($field_name . '_target_id'));
     }
   }
 }