diff --git a/hash_list.h b/hash_list.h
index 5e817c6e..94921f83 100644
--- a/hash_list.h
+++ b/hash_list.h
@@ -42,9 +42,9 @@ class hash_list {
     using value_type = T;
     using size_type = std::size_t;
     using difference_type = std::ptrdiff_t;
-    using reference = reference;
+//    using reference = reference;
     using const_reference = const T &;
-    using iterator = iterator;
+//    using iterator = iterator;
     using const_iterator = typename decltype(data)::const_iterator;
     using reverse_iterator = std::reverse_iterator<iterator>;
     using const_reverse_iterator = std::reverse_iterator<const_iterator>;