diff --git a/libcxx/include/__config b/libcxx/include/__config
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -1002,6 +1002,14 @@
 #  define _LIBCPP_CONSTEXPR_AFTER_CXX17
 #endif
 
+#if _LIBCPP_STD_VER > 17 && \
+    !defined(_LIBCPP_HAS_NO_CXX14_CONSTEXPR) && \
+    !defined(_LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED)
+#  define _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED constexpr
+#else
+#  define _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED
+#endif
+
 // The _LIBCPP_NODISCARD_ATTRIBUTE should only be used to define other
 // NODISCARD macros to the correct attribute.
 #if __has_cpp_attribute(nodiscard) || defined(_LIBCPP_COMPILER_MSVC)
diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -1727,7 +1727,7 @@
 }
 
 template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED
 _OutputIterator
 copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
 {
@@ -1780,7 +1780,7 @@
 }
 
 template <class _BidirectionalIterator1, class _BidirectionalIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED
 _BidirectionalIterator2
 copy_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
               _BidirectionalIterator2 __result)
@@ -1818,7 +1818,7 @@
 // copy_n
 
 template<class _InputIterator, class _Size, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED
 typename enable_if
 <
     __is_input_iterator<_InputIterator>::value &&
@@ -1844,7 +1844,7 @@
 }
 
 template<class _InputIterator, class _Size, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED
 typename enable_if
 <
     __is_random_access_iterator<_InputIterator>::value,
diff --git a/libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/copy.pass.cpp b/libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/copy.pass.cpp
--- a/libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/copy.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/copy.pass.cpp
@@ -79,7 +79,7 @@
 {
     test();
 
-#if TEST_STD_VER > 17
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED)
     static_assert(test());
 #endif
 
diff --git a/libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/copy_backward.pass.cpp b/libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/copy_backward.pass.cpp
--- a/libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/copy_backward.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/copy_backward.pass.cpp
@@ -58,7 +58,7 @@
 {
     test();
 
-#if TEST_STD_VER > 17
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED)
     static_assert(test());
 #endif
 
diff --git a/libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/copy_n.pass.cpp b/libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/copy_n.pass.cpp
--- a/libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/copy_n.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/copy_n.pass.cpp
@@ -82,7 +82,7 @@
 {
     test();
 
-#if TEST_STD_VER > 17
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED)
     static_assert(test());
 #endif