diff --git a/toml/types.hpp b/toml/types.hpp
index e752507..6e7fbaa 100644
--- a/toml/types.hpp
+++ b/toml/types.hpp
@@ -31,11 +31,11 @@ using floating       = double; // "float" is a keyward, cannot use it here.
 // - local_date
 // - local_time
 
-// default toml::value and default array/table
-using value = basic_value<discard_comments, std::unordered_map, std::vector>;
-// TODO: consider to move these after including `value.hpp`
-using array = std::vector<value>;             // typename value::array_type;
-using table = std::unordered_map<key, value>; // typename value::table_type;
+// default toml::value and default array/table. these are defined after defining
+// basic_value itself.
+// using value = basic_value<discard_comments, std::unordered_map, std::vector>;
+// using array = typename value::array_type;
+// using table = typename value::table_type;
 
 enum class value_t : std::uint8_t
 {
diff --git a/toml/value.hpp b/toml/value.hpp
index 6687ccd..8e7250f 100644
--- a/toml/value.hpp
+++ b/toml/value.hpp
@@ -960,6 +960,11 @@ class basic_value
     };
 };
 
+// default toml::value and default array/table.
+using value = basic_value<discard_comments, std::unordered_map, std::vector>;
+using array = typename value::array_type;
+using table = typename value::table_type;
+
 namespace detail
 {
 template<typename C,