diff --git a/doc/api.md b/doc/api.md
index 61e5c3de..b6742a6c 100644
--- a/doc/api.md
+++ b/doc/api.md
@@ -653,8 +653,6 @@ if an argument type doesn't match its format specification.
 The optional header `fmt/xchar.h` provides support for `wchar_t` and
 exotic character types.
 
-::: is_char
-
 ::: wstring_view
 
 ::: wformat_context
diff --git a/include/fmt/base.h b/include/fmt/base.h
index bd2e13c3..a97c298a 100644
--- a/include/fmt/base.h
+++ b/include/fmt/base.h
@@ -607,19 +607,6 @@ template <typename Char> class basic_string_view {
 
 using string_view = basic_string_view<char>;
 
-// DEPRECATED! Will be merged with is_char and moved to detail.
-template <typename T> struct is_xchar : std::false_type {};
-template <> struct is_xchar<wchar_t> : std::true_type {};
-template <> struct is_xchar<char16_t> : std::true_type {};
-template <> struct is_xchar<char32_t> : std::true_type {};
-#ifdef __cpp_char8_t
-template <> struct is_xchar<char8_t> : std::true_type {};
-#endif
-
-// Specifies if `T` is a character (code unit) type.
-template <typename T> struct is_char : is_xchar<T> {};
-template <> struct is_char<char> : std::true_type {};
-
 template <typename T> class basic_appender;
 using appender = basic_appender<char>;
 
@@ -916,6 +903,20 @@ FMT_END_EXPORT
 
 namespace detail {
 
+// DEPRECATED! Will be merged with is_char
+template <typename T> struct is_xchar : std::false_type {};
+template <> struct is_xchar<wchar_t> : std::true_type {};
+template <> struct is_xchar<char16_t> : std::true_type {};
+template <> struct is_xchar<char32_t> : std::true_type {};
+#ifdef __cpp_char8_t
+template <>
+struct is_xchar<char8_t> : bool_constant<detail::is_utf8_enabled> {};
+#endif
+
+// Specifies if `T` is a character (code unit) type.
+template <typename T> struct is_char : is_xchar<T> {};
+template <> struct is_char<char> : std::true_type {};
+
 // Constructs fmt::basic_string_view<Char> from types implicitly convertible
 // to it, deducing Char. Explicitly convertible types such as the ones returned
 // from FMT_STRING are intentionally excluded.
diff --git a/include/fmt/xchar.h b/include/fmt/xchar.h
index 598fea75..c0240a3e 100644
--- a/include/fmt/xchar.h
+++ b/include/fmt/xchar.h
@@ -112,10 +112,6 @@ inline auto runtime(wstring_view s) -> runtime_format_string<wchar_t> {
   return {{s}};
 }
 
-#ifdef __cpp_char8_t
-template <> struct is_char<char8_t> : bool_constant<detail::is_utf8_enabled> {};
-#endif
-
 template <typename... T>
 constexpr auto make_wformat_args(T&... args)
     -> decltype(fmt::make_format_args<wformat_context>(args...)) {