diff --git a/libcxx/include/string b/libcxx/include/string
--- a/libcxx/include/string
+++ b/libcxx/include/string
@@ -4736,7 +4736,7 @@
 
 #ifndef _LIBCPP_HAS_NO_CHAR8_T
     inline _LIBCPP_HIDE_FROM_ABI constexpr
-    basic_string<char8_t> operator "" s(const char8_t *__str, size_t __len) _NOEXCEPT
+    basic_string<char8_t> operator "" s(const char8_t *__str, size_t __len)
     {
         return basic_string<char8_t> (__str, __len);
     }
diff --git a/libcxx/test/std/strings/basic.string.literals/noexcept.compile.pass.cpp b/libcxx/test/std/strings/basic.string.literals/noexcept.compile.pass.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/std/strings/basic.string.literals/noexcept.compile.pass.cpp
@@ -0,0 +1,21 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11
+
+#include <string>
+
+static_assert(!noexcept(std::operator""s(std::declval<const char*>(), std::declval<int>())));
+#ifndef TEST_HAS_NO_CHAR8_T
+static_assert(!noexcept(std::operator""s(std::declval<const char8_t*>(), std::declval<int>())));
+#endif
+static_assert(!noexcept(std::operator""s(std::declval<const char16_t*>(), std::declval<int>())));
+static_assert(!noexcept(std::operator""s(std::declval<const char32_t*>(), std::declval<int>())));
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+static_assert(!noexcept(std::operator""s(std::declval<const wchar_t*>(), std::declval<int>())));
+#endif
diff --git a/libcxx/test/std/strings/string.classes/typedefs.compile.pass.cpp b/libcxx/test/std/strings/string.classes/typedefs.compile.pass.cpp
--- a/libcxx/test/std/strings/string.classes/typedefs.compile.pass.cpp
+++ b/libcxx/test/std/strings/string.classes/typedefs.compile.pass.cpp
@@ -26,7 +26,7 @@
 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
 static_assert((std::is_same<std::wstring, std::basic_string<wchar_t> >::value), "");
 #endif
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
 static_assert((std::is_same<std::u8string, std::basic_string<char8_t> >::value), "");
 #endif
 static_assert((std::is_same<std::u16string, std::basic_string<char16_t> >::value), "");