diff --git a/search/Search.hh b/search/Search.hh
index de4cd1a9..4d39f102 100644
--- a/search/Search.hh
+++ b/search/Search.hh
@@ -575,12 +575,14 @@ protected:
   TagIndex tag_capacity_;
   Tag **tags_;
   TagIndex tag_next_;
-  Vector<TagIndex> tag_free_indices_;
+  // Holes in tags_ left by deleting filter tags.
+  std::vector<TagIndex> tag_free_indices_;
   std::mutex tag_lock_;
   TagGroupSet *tag_group_set_;
   TagGroup **tag_groups_;
   TagGroupIndex tag_group_next_;
-  Vector<TagIndex> tag_group_free_indices_;
+  // Holes in tag_groups_ left by deleting filter tag groups.
+  std::vector<TagIndex> tag_group_free_indices_;
   // Capacity of tag_groups_.
   TagGroupIndex tag_group_capacity_;
   std::mutex tag_group_lock_;