diff --git a/libcxx/include/__config b/libcxx/include/__config
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -914,10 +914,6 @@
 #define _LIBCPP_WCTYPE_IS_MASK
 #endif
 
-#if _LIBCPP_STD_VER <= 17 || !defined(__cpp_char8_t)
-#define _LIBCPP_HAS_NO_CHAR8_T
-#endif
-
 // Deprecation macros.
 //
 // Deprecations warnings are always enabled, except when users explicitly opt-out
@@ -958,7 +954,7 @@
 #  define _LIBCPP_DEPRECATED_IN_CXX20
 #endif
 
-#if !defined(_LIBCPP_HAS_NO_CHAR8_T)
+#if  _LIBCPP_STD_VER <= 17
 #  define _LIBCPP_DEPRECATED_WITH_CHAR8_T _LIBCPP_DEPRECATED
 #else
 #  define _LIBCPP_DEPRECATED_WITH_CHAR8_T
diff --git a/libcxx/include/__functional/hash.h b/libcxx/include/__functional/hash.h
--- a/libcxx/include/__functional/hash.h
+++ b/libcxx/include/__functional/hash.h
@@ -507,7 +507,6 @@
     size_t operator()(unsigned char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
 };
 
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 template <>
 struct _LIBCPP_TEMPLATE_VIS hash<char8_t>
@@ -523,7 +522,6 @@
     _LIBCPP_INLINE_VISIBILITY
     size_t operator()(char8_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
 };
-#endif // !_LIBCPP_HAS_NO_CHAR8_T
 
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
 
diff --git a/libcxx/include/__locale b/libcxx/include/__locale
--- a/libcxx/include/__locale
+++ b/libcxx/include/__locale
@@ -1159,7 +1159,7 @@
     virtual int do_max_length() const  _NOEXCEPT;
 };
 
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 
 // template <> class codecvt<char16_t, char8_t, mbstate_t> // C++20
 
@@ -1247,7 +1247,7 @@
     virtual int do_max_length() const  _NOEXCEPT;
 };
 
-#endif
+#endif // _LIBCPP_STD_VER > 17
 
 // template <> class codecvt<char32_t, char, mbstate_t> // deprecated in C++20
 
@@ -1335,7 +1335,7 @@
     virtual int do_max_length() const  _NOEXCEPT;
 };
 
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 
 // template <> class codecvt<char32_t, char8_t, mbstate_t> // C++20
 
@@ -1423,7 +1423,7 @@
     virtual int do_max_length() const  _NOEXCEPT;
 };
 
-#endif
+#endif // _LIBCPP_STD_VER > 17
 
 // template <class _InternT, class _ExternT, class _StateT> class codecvt_byname
 
@@ -1453,7 +1453,7 @@
 _LIBCPP_EXTERN_TEMPLATE_EVEN_IN_DEBUG_MODE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<wchar_t, char, mbstate_t>)
 _LIBCPP_EXTERN_TEMPLATE_EVEN_IN_DEBUG_MODE(class _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<char16_t, char, mbstate_t>) // deprecated in C++20
 _LIBCPP_EXTERN_TEMPLATE_EVEN_IN_DEBUG_MODE(class _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<char32_t, char, mbstate_t>) // deprecated in C++20
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 _LIBCPP_EXTERN_TEMPLATE_EVEN_IN_DEBUG_MODE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<char16_t, char8_t, mbstate_t>) // C++20
 _LIBCPP_EXTERN_TEMPLATE_EVEN_IN_DEBUG_MODE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<char32_t, char8_t, mbstate_t>) // C++20
 #endif
diff --git a/libcxx/include/__string b/libcxx/include/__string
--- a/libcxx/include/__string
+++ b/libcxx/include/__string
@@ -551,7 +551,7 @@
 #endif
 }
 
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 
 template <>
 struct _LIBCPP_TEMPLATE_VIS char_traits<char8_t>
@@ -660,7 +660,7 @@
     return nullptr;
 }
 
-#endif // #_LIBCPP_HAS_NO_CHAR8_T
+#endif // _LIBCPP_STD_VER > 17
 
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
 
diff --git a/libcxx/include/__utility/cmp.h b/libcxx/include/__utility/cmp.h
--- a/libcxx/include/__utility/cmp.h
+++ b/libcxx/include/__utility/cmp.h
@@ -30,10 +30,7 @@
 
 template<class _Tp>
 concept __is_safe_integral_cmp = is_integral_v<_Tp> &&
-                      !_IsSameAsAny<_Tp, bool, char,
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
-                                    char8_t,
-#endif
+                      !_IsSameAsAny<_Tp, bool, char, char8_t,
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
                                     char16_t, char32_t,
 #endif
diff --git a/libcxx/include/atomic b/libcxx/include/atomic
--- a/libcxx/include/atomic
+++ b/libcxx/include/atomic
@@ -1137,7 +1137,7 @@
 #if defined(__CLANG_ATOMIC_BOOL_LOCK_FREE)
 # define ATOMIC_BOOL_LOCK_FREE      __CLANG_ATOMIC_BOOL_LOCK_FREE
 # define ATOMIC_CHAR_LOCK_FREE      __CLANG_ATOMIC_CHAR_LOCK_FREE
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 # define ATOMIC_CHAR8_T_LOCK_FREE   __CLANG_ATOMIC_CHAR8_T_LOCK_FREE
 #endif
 # define ATOMIC_CHAR16_T_LOCK_FREE  __CLANG_ATOMIC_CHAR16_T_LOCK_FREE
@@ -1151,7 +1151,7 @@
 #elif defined(__GCC_ATOMIC_BOOL_LOCK_FREE)
 # define ATOMIC_BOOL_LOCK_FREE      __GCC_ATOMIC_BOOL_LOCK_FREE
 # define ATOMIC_CHAR_LOCK_FREE      __GCC_ATOMIC_CHAR_LOCK_FREE
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 # define ATOMIC_CHAR8_T_LOCK_FREE   __GCC_ATOMIC_CHAR8_T_LOCK_FREE
 #endif
 # define ATOMIC_CHAR16_T_LOCK_FREE  __GCC_ATOMIC_CHAR16_T_LOCK_FREE
@@ -1468,7 +1468,7 @@
 template<> struct __cxx_is_always_lock_free<char> { enum { __value = 2 == ATOMIC_CHAR_LOCK_FREE }; };
 template<> struct __cxx_is_always_lock_free<signed char> { enum { __value = 2 == ATOMIC_CHAR_LOCK_FREE }; };
 template<> struct __cxx_is_always_lock_free<unsigned char> { enum { __value = 2 == ATOMIC_CHAR_LOCK_FREE }; };
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 template<> struct __cxx_is_always_lock_free<char8_t> { enum { __value = 2 == ATOMIC_CHAR8_T_LOCK_FREE }; };
 #endif
 template<> struct __cxx_is_always_lock_free<char16_t> { enum { __value = 2 == ATOMIC_CHAR16_T_LOCK_FREE }; };
@@ -2756,7 +2756,7 @@
 typedef atomic<unsigned long>      atomic_ulong;
 typedef atomic<long long>          atomic_llong;
 typedef atomic<unsigned long long> atomic_ullong;
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 typedef atomic<char8_t>            atomic_char8_t;
 #endif
 typedef atomic<char16_t>           atomic_char16_t;
diff --git a/libcxx/include/cstddef b/libcxx/include/cstddef
--- a/libcxx/include/cstddef
+++ b/libcxx/include/cstddef
@@ -59,7 +59,7 @@
 template <>          struct __libcpp_is_integral<signed char>        { enum { value = 1 }; };
 template <>          struct __libcpp_is_integral<unsigned char>      { enum { value = 1 }; };
 template <>          struct __libcpp_is_integral<wchar_t>            { enum { value = 1 }; };
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 template <>          struct __libcpp_is_integral<char8_t>            { enum { value = 1 }; };
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/include/filesystem b/libcxx/include/filesystem
--- a/libcxx/include/filesystem
+++ b/libcxx/include/filesystem
@@ -558,7 +558,7 @@
   static const bool value = true;
   using __char_type = wchar_t;
 };
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 template <>
 struct __can_convert_char<char8_t> {
   static const bool value = true;
@@ -586,7 +586,7 @@
 #endif
 }
 
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 typedef u8string __u8_string;
 #else
 typedef string __u8_string;
@@ -893,7 +893,7 @@
   }
 };
 
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 template <>
 struct _PathExport<char8_t> {
   typedef __narrow_to_utf8<sizeof(wchar_t) * __CHAR_BIT__> _Narrower;
@@ -903,7 +903,7 @@
     _Narrower()(back_inserter(__dest), __src.data(), __src.data() + __src.size());
   }
 };
-#endif /* !_LIBCPP_HAS_NO_CHAR8_T */
+#endif /* _LIBCPP_STD_VER > 17 */
 #endif /* _LIBCPP_WIN32API */
 
 class _LIBCPP_TYPE_VIS path {
@@ -1264,7 +1264,7 @@
 #else /* _LIBCPP_WIN32API */
 
   _LIBCPP_INLINE_VISIBILITY _VSTD::string string() const { return __pn_; }
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
   _LIBCPP_INLINE_VISIBILITY _VSTD::u8string u8string() const { return _VSTD::u8string(__pn_.begin(), __pn_.end()); }
 #else
   _LIBCPP_INLINE_VISIBILITY _VSTD::string u8string() const { return __pn_; }
@@ -1296,7 +1296,7 @@
 
   // generic format observers
   _VSTD::string generic_string() const { return __pn_; }
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
   _VSTD::u8string generic_u8string() const { return _VSTD::u8string(__pn_.begin(), __pn_.end()); }
 #else
   _VSTD::string generic_u8string() const { return __pn_; }
@@ -1520,7 +1520,7 @@
     typename enable_if<__is_pathable<_InputIt>::value, path>::type
     u8path(_InputIt __f, _InputIt __l) {
   static_assert(
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
       is_same<typename __is_pathable<_InputIt>::__char_type, char8_t>::value ||
 #endif
       is_same<typename __is_pathable<_InputIt>::__char_type, char>::value,
@@ -1544,7 +1544,7 @@
     typename enable_if<__is_pathable<_InputIt>::value, path>::type
     u8path(_InputIt __f, _NullSentinel) {
   static_assert(
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
       is_same<typename __is_pathable<_InputIt>::__char_type, char8_t>::value ||
 #endif
       is_same<typename __is_pathable<_InputIt>::__char_type, char>::value,
@@ -1567,7 +1567,7 @@
     typename enable_if<__is_pathable<_Source>::value, path>::type
     u8path(const _Source& __s) {
   static_assert(
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
       is_same<typename __is_pathable<_Source>::__char_type, char8_t>::value ||
 #endif
       is_same<typename __is_pathable<_Source>::__char_type, char>::value,
diff --git a/libcxx/include/iosfwd b/libcxx/include/iosfwd
--- a/libcxx/include/iosfwd
+++ b/libcxx/include/iosfwd
@@ -107,7 +107,7 @@
 
 template<class _CharT>  struct _LIBCPP_TEMPLATE_VIS char_traits;
 template<> struct char_traits<char>;
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 template<> struct char_traits<char8_t>;
 #endif
 template<> struct char_traits<char16_t>;
@@ -221,7 +221,7 @@
 template <class _State>             class _LIBCPP_TEMPLATE_VIS fpos;
 typedef fpos<mbstate_t>    streampos;
 typedef fpos<mbstate_t>    wstreampos;
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 typedef fpos<mbstate_t>    u8streampos;
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/include/string b/libcxx/include/string
--- a/libcxx/include/string
+++ b/libcxx/include/string
@@ -668,7 +668,7 @@
 
 #endif // _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
 
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 typedef basic_string<char8_t> u8string;
 #endif
 
@@ -680,7 +680,7 @@
 template<class _CharT, class _Traits, class _Allocator>
 class
     _LIBCPP_TEMPLATE_VIS
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
     _LIBCPP_PREFERRED_NAME(u8string)
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
@@ -4555,7 +4555,7 @@
         return basic_string<wchar_t> (__str, __len);
     }
 
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
     inline _LIBCPP_INLINE_VISIBILITY
     basic_string<char8_t> operator "" s(const char8_t *__str, size_t __len) _NOEXCEPT
     {
diff --git a/libcxx/include/string_view b/libcxx/include/string_view
--- a/libcxx/include/string_view
+++ b/libcxx/include/string_view
@@ -212,7 +212,7 @@
     class _LIBCPP_TEMPLATE_VIS basic_string_view;
 
 typedef basic_string_view<char>     string_view;
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
 typedef basic_string_view<char8_t>  u8string_view;
 #endif
 typedef basic_string_view<char16_t> u16string_view;
@@ -222,7 +222,7 @@
 template<class _CharT, class _Traits>
 class
     _LIBCPP_PREFERRED_NAME(string_view)
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
     _LIBCPP_PREFERRED_NAME(u8string_view)
 #endif
     _LIBCPP_PREFERRED_NAME(u16string_view)
@@ -866,7 +866,7 @@
         return basic_string_view<wchar_t> (__str, __len);
     }
 
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
+#if _LIBCPP_STD_VER > 17
     inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
     basic_string_view<char8_t> operator "" sv(const char8_t *__str, size_t __len) _NOEXCEPT
     {
diff --git a/libcxx/include/version b/libcxx/include/version
--- a/libcxx/include/version
+++ b/libcxx/include/version
@@ -289,9 +289,7 @@
 # define __cpp_lib_bit_cast                             201806L
 // # define __cpp_lib_bitops                               201907L
 # define __cpp_lib_bounded_array_traits                 201902L
-# if !defined(_LIBCPP_HAS_NO_CHAR8_T)
-#   define __cpp_lib_char8_t                            201811L
-# endif
+# define __cpp_lib_char8_t                              201811L
 # define __cpp_lib_concepts                             202002L
 # define __cpp_lib_constexpr_algorithms                 201806L
 // # define __cpp_lib_constexpr_complex                    201711L
diff --git a/libcxx/test/std/atomics/atomics.lockfree/isalwayslockfree.pass.cpp b/libcxx/test/std/atomics/atomics.lockfree/isalwayslockfree.pass.cpp
--- a/libcxx/test/std/atomics/atomics.lockfree/isalwayslockfree.pass.cpp
+++ b/libcxx/test/std/atomics/atomics.lockfree/isalwayslockfree.pass.cpp
@@ -74,7 +74,7 @@
     CHECK_ALWAYS_LOCK_FREE(char);
     CHECK_ALWAYS_LOCK_FREE(signed char);
     CHECK_ALWAYS_LOCK_FREE(unsigned char);
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     CHECK_ALWAYS_LOCK_FREE(char8_t);
 #endif
     CHECK_ALWAYS_LOCK_FREE(char16_t);
@@ -125,7 +125,7 @@
     static_assert(std::atomic<char>::is_always_lock_free == (2 == ATOMIC_CHAR_LOCK_FREE), "");
     static_assert(std::atomic<signed char>::is_always_lock_free == (2 == ATOMIC_CHAR_LOCK_FREE), "");
     static_assert(std::atomic<unsigned char>::is_always_lock_free == (2 == ATOMIC_CHAR_LOCK_FREE), "");
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     static_assert(std::atomic<char8_t>::is_always_lock_free == (2 == ATOMIC_CHAR8_T_LOCK_FREE), "");
 #endif
     static_assert(std::atomic<char16_t>::is_always_lock_free == (2 == ATOMIC_CHAR16_T_LOCK_FREE), "");
diff --git a/libcxx/test/std/atomics/atomics.lockfree/lockfree.pass.cpp b/libcxx/test/std/atomics/atomics.lockfree/lockfree.pass.cpp
--- a/libcxx/test/std/atomics/atomics.lockfree/lockfree.pass.cpp
+++ b/libcxx/test/std/atomics/atomics.lockfree/lockfree.pass.cpp
@@ -35,7 +35,7 @@
     assert(ATOMIC_CHAR_LOCK_FREE == 0 ||
            ATOMIC_CHAR_LOCK_FREE == 1 ||
            ATOMIC_CHAR_LOCK_FREE == 2);
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     assert(ATOMIC_CHAR8_T_LOCK_FREE == 0 ||
            ATOMIC_CHAR8_T_LOCK_FREE == 1 ||
            ATOMIC_CHAR8_T_LOCK_FREE == 2);
diff --git a/libcxx/test/std/atomics/atomics.types.generic/integral.pass.cpp b/libcxx/test/std/atomics/atomics.types.generic/integral.pass.cpp
--- a/libcxx/test/std/atomics/atomics.types.generic/integral.pass.cpp
+++ b/libcxx/test/std/atomics/atomics.types.generic/integral.pass.cpp
@@ -176,7 +176,7 @@
     test<std::atomic_ulong, unsigned long>();
     test<std::atomic_llong, long long>();
     test<std::atomic_ullong, unsigned long long>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<std::atomic_char8_t, char8_t>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/atomics/atomics.types.generic/integral_typedefs.pass.cpp b/libcxx/test/std/atomics/atomics.types.generic/integral_typedefs.pass.cpp
--- a/libcxx/test/std/atomics/atomics.types.generic/integral_typedefs.pass.cpp
+++ b/libcxx/test/std/atomics/atomics.types.generic/integral_typedefs.pass.cpp
@@ -57,7 +57,7 @@
     static_assert((std::is_same<std::atomic<long long>, std::atomic_llong>::value), "");
     static_assert((std::is_same<std::atomic<unsigned long long>, std::atomic_ullong>::value), "");
     static_assert((std::is_same<std::atomic<wchar_t>, std::atomic_wchar_t>::value), "");
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     static_assert((std::is_same<std::atomic<char8_t>, std::atomic_char8_t>::value), "");
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/atomics/types.pass.cpp b/libcxx/test/std/atomics/types.pass.cpp
--- a/libcxx/test/std/atomics/types.pass.cpp
+++ b/libcxx/test/std/atomics/types.pass.cpp
@@ -113,7 +113,7 @@
     test<unsigned long>      ();
     test<long long>          ();
     test<unsigned long long> ();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t>            ();
 #endif
     test<char16_t>           ();
diff --git a/libcxx/test/std/input.output/filesystems/class.path/path.member/path.construct/source.pass.cpp b/libcxx/test/std/input.output/filesystems/class.path/path.member/path.construct/source.pass.cpp
--- a/libcxx/test/std/input.output/filesystems/class.path/path.member/path.construct/source.pass.cpp
+++ b/libcxx/test/std/input.output/filesystems/class.path/path.member/path.construct/source.pass.cpp
@@ -126,7 +126,7 @@
 int main(int, char**) {
   for (auto const& MS : PathList) {
     RunTestCase<char>(MS);
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     RunTestCase<char8_t>(MS);
 #endif
     RunTestCase<wchar_t>(MS);
diff --git a/libcxx/test/std/input.output/filesystems/class.path/path.member/path.generic.obs/named_overloads.pass.cpp b/libcxx/test/std/input.output/filesystems/class.path/path.member/path.generic.obs/named_overloads.pass.cpp
--- a/libcxx/test/std/input.output/filesystems/class.path/path.member/path.generic.obs/named_overloads.pass.cpp
+++ b/libcxx/test/std/input.output/filesystems/class.path/path.member/path.generic.obs/named_overloads.pass.cpp
@@ -52,7 +52,7 @@
     assert(s == (const char*)MS);
   }
   {
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     ASSERT_SAME_TYPE(decltype(p.generic_u8string()), std::u8string);
     std::u8string s = p.generic_u8string();
     assert(s == (const char8_t*)MS);
diff --git a/libcxx/test/std/input.output/filesystems/class.path/path.member/path.native.obs/named_overloads.pass.cpp b/libcxx/test/std/input.output/filesystems/class.path/path.member/path.native.obs/named_overloads.pass.cpp
--- a/libcxx/test/std/input.output/filesystems/class.path/path.member/path.native.obs/named_overloads.pass.cpp
+++ b/libcxx/test/std/input.output/filesystems/class.path/path.member/path.native.obs/named_overloads.pass.cpp
@@ -46,7 +46,7 @@
     assert(s == value);
   }
   {
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     ASSERT_SAME_TYPE(decltype(p.u8string()), std::u8string);
     std::u8string s = p.u8string();
     assert(s == (const char8_t*)MS);
diff --git a/libcxx/test/std/input.output/filesystems/class.path/path.nonmember/path.factory.pass.cpp b/libcxx/test/std/input.output/filesystems/class.path/path.nonmember/path.factory.pass.cpp
--- a/libcxx/test/std/input.output/filesystems/class.path/path.nonmember/path.factory.pass.cpp
+++ b/libcxx/test/std/input.output/filesystems/class.path/path.nonmember/path.factory.pass.cpp
@@ -49,8 +49,7 @@
     path p = fs::u8path(In3, In3End);
     assert(p == In1);
   }
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t) && defined(_LIBCPP_VERSION) && \
-    !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#if TEST_STD_VER > 17 && defined(_LIBCPP_VERSION) && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
   const char8_t* u8In1 = u8"abcd/efg";
   const std::u8string u8In2(u8In1);
   const auto u8In3 = u8In2.begin();
diff --git a/libcxx/test/std/language.support/support.limits/limits/is_specialized.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/is_specialized.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/is_specialized.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/is_specialized.pass.cpp
@@ -46,7 +46,7 @@
     test<bool>();
     test<char>();
     test<wchar_t>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/const_data_members.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/const_data_members.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/const_data_members.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/const_data_members.pass.cpp
@@ -100,7 +100,7 @@
     TEST_NUMERIC_LIMITS(volatile wchar_t)
     TEST_NUMERIC_LIMITS(const volatile wchar_t)
 
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     // char8_t
     TEST_NUMERIC_LIMITS(char8_t)
     TEST_NUMERIC_LIMITS(const char8_t)
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/denorm_min.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/denorm_min.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/denorm_min.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/denorm_min.pass.cpp
@@ -33,7 +33,7 @@
     test<signed char>(0);
     test<unsigned char>(0);
     test<wchar_t>(0);
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t>(0);
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/digits.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/digits.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/digits.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/digits.pass.cpp
@@ -32,7 +32,7 @@
     test<signed char, 7>();
     test<unsigned char, 8>();
     test<wchar_t, std::numeric_limits<wchar_t>::is_signed ? sizeof(wchar_t)*8-1 : sizeof(wchar_t)*8>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, 8>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/digits10.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/digits10.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/digits10.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/digits10.pass.cpp
@@ -36,7 +36,7 @@
     test<signed char, 2>();
     test<unsigned char, 2>();
     test<wchar_t, 5*sizeof(wchar_t)/2-1>();  // 4 -> 9 and 2 -> 4
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, 2>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/epsilon.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/epsilon.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/epsilon.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/epsilon.pass.cpp
@@ -33,7 +33,7 @@
     test<signed char>(0);
     test<unsigned char>(0);
     test<wchar_t>(0);
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t>(0);
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_denorm.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_denorm.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_denorm.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_denorm.pass.cpp
@@ -31,7 +31,7 @@
     test<signed char, std::denorm_absent>();
     test<unsigned char, std::denorm_absent>();
     test<wchar_t, std::denorm_absent>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, std::denorm_absent>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_denorm_loss.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_denorm_loss.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_denorm_loss.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_denorm_loss.pass.cpp
@@ -31,7 +31,7 @@
     test<signed char, false>();
     test<unsigned char, false>();
     test<wchar_t, false>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, false>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_infinity.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_infinity.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_infinity.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_infinity.pass.cpp
@@ -31,7 +31,7 @@
     test<signed char, false>();
     test<unsigned char, false>();
     test<wchar_t, false>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, false>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_quiet_NaN.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_quiet_NaN.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_quiet_NaN.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_quiet_NaN.pass.cpp
@@ -31,7 +31,7 @@
     test<signed char, false>();
     test<unsigned char, false>();
     test<wchar_t, false>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, false>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_signaling_NaN.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_signaling_NaN.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_signaling_NaN.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/has_signaling_NaN.pass.cpp
@@ -31,7 +31,7 @@
     test<signed char, false>();
     test<unsigned char, false>();
     test<wchar_t, false>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, false>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/infinity.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/infinity.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/infinity.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/infinity.pass.cpp
@@ -35,7 +35,7 @@
     test<signed char>(0);
     test<unsigned char>(0);
     test<wchar_t>(0);
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t>(0);
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_bounded.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_bounded.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_bounded.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_bounded.pass.cpp
@@ -31,7 +31,7 @@
     test<signed char, true>();
     test<unsigned char, true>();
     test<wchar_t, true>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, true>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_exact.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_exact.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_exact.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_exact.pass.cpp
@@ -31,7 +31,7 @@
     test<signed char, true>();
     test<unsigned char, true>();
     test<wchar_t, true>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, true>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_iec559.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_iec559.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_iec559.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_iec559.pass.cpp
@@ -31,7 +31,7 @@
     test<signed char, false>();
     test<unsigned char, false>();
     test<wchar_t, false>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, false>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_integer.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_integer.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_integer.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_integer.pass.cpp
@@ -31,7 +31,7 @@
     test<signed char, true>();
     test<unsigned char, true>();
     test<wchar_t, true>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, true>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_modulo.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_modulo.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_modulo.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_modulo.pass.cpp
@@ -31,7 +31,7 @@
     test<signed char, false>();
     test<unsigned char, true>();
 //    test<wchar_t, false>(); // don't know
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, true>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_signed.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_signed.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_signed.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/is_signed.pass.cpp
@@ -31,7 +31,7 @@
     test<signed char, true>();
     test<unsigned char, false>();
     test<wchar_t, wchar_t(-1) < wchar_t(0)>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, false>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/lowest.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/lowest.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/lowest.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/lowest.pass.cpp
@@ -39,7 +39,7 @@
     test<signed char>(SCHAR_MIN);
     test<unsigned char>(0);
     test<wchar_t>(WCHAR_MIN);
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t>(0);
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max.pass.cpp
@@ -39,7 +39,7 @@
     test<signed char>(SCHAR_MAX);
     test<unsigned char>(UCHAR_MAX);
     test<wchar_t>(WCHAR_MAX);
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t>(UCHAR_MAX); // ??
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max_digits10.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max_digits10.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max_digits10.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max_digits10.pass.cpp
@@ -32,7 +32,7 @@
     test<signed char, 0>();
     test<unsigned char, 0>();
     test<wchar_t, 0>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, 0>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max_exponent.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max_exponent.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max_exponent.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max_exponent.pass.cpp
@@ -32,7 +32,7 @@
     test<signed char, 0>();
     test<unsigned char, 0>();
     test<wchar_t, 0>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, 0>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max_exponent10.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max_exponent10.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max_exponent10.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/max_exponent10.pass.cpp
@@ -32,7 +32,7 @@
     test<signed char, 0>();
     test<unsigned char, 0>();
     test<wchar_t, 0>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, 0>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/min.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/min.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/min.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/min.pass.cpp
@@ -39,7 +39,7 @@
     test<signed char>(SCHAR_MIN);
     test<unsigned char>(0);
     test<wchar_t>(WCHAR_MIN);
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t>(0);
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/min_exponent.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/min_exponent.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/min_exponent.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/min_exponent.pass.cpp
@@ -32,7 +32,7 @@
     test<signed char, 0>();
     test<unsigned char, 0>();
     test<wchar_t, 0>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, 0>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/min_exponent10.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/min_exponent10.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/min_exponent10.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/min_exponent10.pass.cpp
@@ -32,7 +32,7 @@
     test<signed char, 0>();
     test<unsigned char, 0>();
     test<wchar_t, 0>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, 0>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/quiet_NaN.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/quiet_NaN.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/quiet_NaN.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/quiet_NaN.pass.cpp
@@ -52,7 +52,7 @@
     test<signed char>();
     test<unsigned char>();
     test<wchar_t>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/radix.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/radix.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/radix.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/radix.pass.cpp
@@ -32,7 +32,7 @@
     test<signed char, 2>();
     test<unsigned char, 2>();
     test<wchar_t, 2>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, 2>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/round_error.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/round_error.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/round_error.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/round_error.pass.cpp
@@ -33,7 +33,7 @@
     test<signed char>(0);
     test<unsigned char>(0);
     test<wchar_t>(0);
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t>(0);
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/round_style.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/round_style.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/round_style.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/round_style.pass.cpp
@@ -31,7 +31,7 @@
     test<signed char, std::round_toward_zero>();
     test<unsigned char, std::round_toward_zero>();
     test<wchar_t, std::round_toward_zero>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, std::round_toward_zero>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/signaling_NaN.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/signaling_NaN.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/signaling_NaN.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/signaling_NaN.pass.cpp
@@ -52,7 +52,7 @@
     test<signed char>();
     test<unsigned char>();
     test<wchar_t>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/tinyness_before.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/tinyness_before.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/tinyness_before.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/tinyness_before.pass.cpp
@@ -31,7 +31,7 @@
     test<signed char, false>();
     test<unsigned char, false>();
     test<wchar_t, false>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, false>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/traps.pass.cpp b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/traps.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/traps.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/limits/numeric.limits.members/traps.pass.cpp
@@ -38,7 +38,7 @@
     test<signed char, integral_types_trap>();
     test<unsigned char, integral_types_trap>();
     test<wchar_t, integral_types_trap>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t, integral_types_trap>();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/atomic.version.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/atomic.version.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/atomic.version.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/atomic.version.pass.cpp
@@ -261,17 +261,11 @@
 #   endif
 # endif
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++20"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++20"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++20"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++20"
 # endif
 
 #elif TEST_STD_VER > 20
@@ -380,17 +374,11 @@
 #   endif
 # endif
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++2b"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++2b"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++2b"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++2b"
 # endif
 
 #endif // TEST_STD_VER > 20
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/filesystem.version.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/filesystem.version.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/filesystem.version.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/filesystem.version.pass.cpp
@@ -66,17 +66,11 @@
 
 #elif TEST_STD_VER == 20
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++20"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++20"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++20"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++20"
 # endif
 
 # if !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem)
@@ -94,17 +88,11 @@
 
 #elif TEST_STD_VER > 20
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++2b"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++2b"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++2b"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++2b"
 # endif
 
 # if !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem)
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/istream.version.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/istream.version.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/istream.version.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/istream.version.pass.cpp
@@ -44,32 +44,20 @@
 
 #elif TEST_STD_VER == 20
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++20"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++20"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++20"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++20"
 # endif
 
 #elif TEST_STD_VER > 20
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++2b"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++2b"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++2b"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++2b"
 # endif
 
 #endif // TEST_STD_VER > 20
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/limits.version.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/limits.version.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/limits.version.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/limits.version.pass.cpp
@@ -42,32 +42,20 @@
 
 #elif TEST_STD_VER == 20
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++20"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++20"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++20"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++20"
 # endif
 
 #elif TEST_STD_VER > 20
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++2b"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++2b"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++2b"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++2b"
 # endif
 
 #endif // TEST_STD_VER > 20
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/locale.version.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/locale.version.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/locale.version.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/locale.version.pass.cpp
@@ -44,32 +44,20 @@
 
 #elif TEST_STD_VER == 20
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++20"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++20"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++20"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++20"
 # endif
 
 #elif TEST_STD_VER > 20
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++2b"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++2b"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++2b"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++2b"
 # endif
 
 #endif // TEST_STD_VER > 20
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/ostream.version.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/ostream.version.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/ostream.version.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/ostream.version.pass.cpp
@@ -44,32 +44,20 @@
 
 #elif TEST_STD_VER == 20
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++20"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++20"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++20"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++20"
 # endif
 
 #elif TEST_STD_VER > 20
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++2b"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++2b"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++2b"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++2b"
 # endif
 
 #endif // TEST_STD_VER > 20
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/string.version.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/string.version.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/string.version.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/string.version.pass.cpp
@@ -169,17 +169,11 @@
 #   error "__cpp_lib_allocator_traits_is_always_equal should have the value 201411L in c++20"
 # endif
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++20"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++20"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++20"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++20"
 # endif
 
 # ifndef __cpp_lib_constexpr_string
@@ -237,17 +231,11 @@
 #   error "__cpp_lib_allocator_traits_is_always_equal should have the value 201411L in c++2b"
 # endif
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++2b"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++2b"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++2b"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++2b"
 # endif
 
 # ifndef __cpp_lib_constexpr_string
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/string_view.version.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/string_view.version.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/string_view.version.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/string_view.version.pass.cpp
@@ -98,17 +98,11 @@
 
 #elif TEST_STD_VER == 20
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++20"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++20"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++20"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++20"
 # endif
 
 # ifndef __cpp_lib_constexpr_string_view
@@ -138,17 +132,11 @@
 
 #elif TEST_STD_VER > 20
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++2b"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++2b"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++2b"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++2b"
 # endif
 
 # ifndef __cpp_lib_constexpr_string_view
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.pass.cpp
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.pass.cpp
@@ -2318,17 +2318,11 @@
 #   error "__cpp_lib_byte should have the value 201603L in c++20"
 # endif
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++20"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++20"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++20"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++20"
 # endif
 
 # ifndef __cpp_lib_chrono
@@ -3469,17 +3463,11 @@
 #   error "__cpp_lib_byte should have the value 201603L in c++2b"
 # endif
 
-# if defined(__cpp_char8_t)
-#   ifndef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should be defined in c++2b"
-#   endif
-#   if __cpp_lib_char8_t != 201811L
-#     error "__cpp_lib_char8_t should have the value 201811L in c++2b"
-#   endif
-# else
-#   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
-#   endif
+# ifndef __cpp_lib_char8_t
+#   error "__cpp_lib_char8_t should be defined in c++2b"
+# endif
+# if __cpp_lib_char8_t != 201811L
+#   error "__cpp_lib_char8_t should have the value 201811L in c++2b"
 # endif
 
 # ifndef __cpp_lib_chrono
diff --git a/libcxx/test/std/strings/basic.string.hash/char_type_hash.fail.cpp b/libcxx/test/std/strings/basic.string.hash/char_type_hash.fail.cpp
--- a/libcxx/test/std/strings/basic.string.hash/char_type_hash.fail.cpp
+++ b/libcxx/test/std/strings/basic.string.hash/char_type_hash.fail.cpp
@@ -57,7 +57,7 @@
     typedef std::basic_string<CharT, trait<CharT> > str_t;
     std::hash<str_t>
         h; // expected-error-re 4 {{{{call to implicitly-deleted default constructor of 'std::hash<str_t>'|implicit instantiation of undefined template}} {{.+}}}}}}
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     // expected-error-re@-2 {{{{call to implicitly-deleted default constructor of 'std::hash<str_t>'|implicit instantiation of undefined template}} {{.+}}}}}}
 #endif
     (void)h;
@@ -66,7 +66,7 @@
 int main(int, char**) {
     test<char>();
     test<wchar_t>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t>();
 #endif
     test<char16_t>();
diff --git a/libcxx/test/std/strings/string.view/string.view.hash/char_type.hash.fail.cpp b/libcxx/test/std/strings/string.view/string.view.hash/char_type.hash.fail.cpp
--- a/libcxx/test/std/strings/string.view/string.view.hash/char_type.hash.fail.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.hash/char_type.hash.fail.cpp
@@ -57,7 +57,7 @@
     typedef std::basic_string_view<CharT, trait<CharT> > strv_t;
     std::hash<strv_t>
         h; // expected-error-re 4 {{{{call to implicitly-deleted default constructor of 'std::hash<strv_t>'|implicit instantiation of undefined template}} {{.+}}}}}}
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     // expected-error-re@-2 {{{{call to implicitly-deleted default constructor of 'std::hash<strv_t>'|implicit instantiation of undefined template}} {{.+}}}}}}
 #endif
     (void)h;
@@ -66,7 +66,7 @@
 int main(int, char**) {
     test<char>();
     test<wchar_t>();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     test<char8_t>();
 #endif
     test<char16_t>();
diff --git a/libcxx/test/support/atomic_helpers.h b/libcxx/test/support/atomic_helpers.h
--- a/libcxx/test/support/atomic_helpers.h
+++ b/libcxx/test/support/atomic_helpers.h
@@ -78,7 +78,7 @@
     TestFunctor<long long>()();
     TestFunctor<unsigned long long>()();
     TestFunctor<wchar_t>()();
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
     TestFunctor<char8_t>()();
 #endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
diff --git a/libcxx/test/support/make_string.h b/libcxx/test/support/make_string.h
--- a/libcxx/test/support/make_string.h
+++ b/libcxx/test/support/make_string.h
@@ -17,7 +17,7 @@
 
 #include <string>
 
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
 #define CHAR8_ONLY(x) x,
 #else
 #define CHAR8_ONLY(x)
@@ -33,7 +33,7 @@
 struct MultiStringType {
   const char* s;
   const wchar_t* w;
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
   const char8_t* u8;
 #endif
   const char16_t* u16;
@@ -41,7 +41,7 @@
 
   constexpr operator const char*() const { return s; }
   constexpr operator const wchar_t*() const { return w; }
-#if TEST_STD_VER > 17 && defined(__cpp_char8_t)
+#if TEST_STD_VER > 17
   constexpr operator const char8_t*() const { return u8; }
 #endif
   constexpr operator const char16_t*() const { return u16; }
diff --git a/libcxx/utils/generate_feature_test_macro_components.py b/libcxx/utils/generate_feature_test_macro_components.py
--- a/libcxx/utils/generate_feature_test_macro_components.py
+++ b/libcxx/utils/generate_feature_test_macro_components.py
@@ -182,8 +182,6 @@
     "name": "__cpp_lib_char8_t",
     "values": { "c++20": 201811 },
     "headers": ["atomic", "filesystem", "istream", "limits", "locale", "ostream", "string", "string_view"],
-    "test_suite_guard": "defined(__cpp_char8_t)",
-    "libcxx_guard": "!defined(_LIBCPP_HAS_NO_CHAR8_T)",
   }, {
     "name": "__cpp_lib_chrono",
     "values": { "c++17": 201611 },