diff --git a/libcxx/include/__config b/libcxx/include/__config
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -1014,6 +1014,12 @@
 #  define _LIBCPP_USE_NO_UNIQUE_ADDRESS 1
 #endif
 
+#if __has_cpp_attribute(clang::trivial_abi) && defined(_LIBCPP_ABI_UNSTABLE)
+#  define _LIBCPP_TRIVIAL_ABI [[clang::trivial_abi]]
+#else
+#  define _LIBCPP_TRIVIAL_ABI
+#endif
+
 #if _LIBCPP_STD_VER > 14 && defined(__cpp_inline_variables) && (__cpp_inline_variables >= 201606L)
 #  define _LIBCPP_INLINE_VAR inline
 #else
diff --git a/libcxx/include/memory b/libcxx/include/memory
--- a/libcxx/include/memory
+++ b/libcxx/include/memory
@@ -2395,7 +2395,7 @@
 };
 
 template <class _Tp, class _Dp = default_delete<_Tp> >
-class _LIBCPP_TEMPLATE_VIS unique_ptr {
+class _LIBCPP_TEMPLATE_VIS _LIBCPP_TRIVIAL_ABI unique_ptr {
 public:
   typedef _Tp element_type;
   typedef _Dp deleter_type;
@@ -2691,7 +2691,7 @@
 
 
 template <class _Tp, class _Dp>
-class _LIBCPP_TEMPLATE_VIS unique_ptr<_Tp[], _Dp> {
+class _LIBCPP_TEMPLATE_VIS _LIBCPP_TRIVIAL_ABI unique_ptr<_Tp[], _Dp> {
 public:
   typedef _Tp element_type;
   typedef _Dp deleter_type;
@@ -3848,7 +3848,7 @@
 template<class _Tp> class _LIBCPP_TEMPLATE_VIS enable_shared_from_this;
 
 template<class _Tp>
-class _LIBCPP_TEMPLATE_VIS shared_ptr
+class _LIBCPP_TEMPLATE_VIS _LIBCPP_TRIVIAL_ABI shared_ptr
 {
 public:
     typedef _Tp element_type;
@@ -5109,7 +5109,7 @@
 #endif  // _LIBCPP_NO_RTTI
 
 template<class _Tp>
-class _LIBCPP_TEMPLATE_VIS weak_ptr
+class _LIBCPP_TEMPLATE_VIS _LIBCPP_TRIVIAL_ABI weak_ptr
 {
 public:
     typedef _Tp element_type;