diff --git a/libcxx/CMakeLists.txt b/libcxx/CMakeLists.txt
--- a/libcxx/CMakeLists.txt
+++ b/libcxx/CMakeLists.txt
@@ -310,8 +310,12 @@
 option(LIBCXX_CONFIGURE_IDE "Configure libcxx for use within an IDE"
       ${LIBCXX_CONFIGURE_IDE_DEFAULT})
 
+set(LIBCXX_HERMETIC_STATIC_LIBRARY_DEFAULT OFF)
+if (WIN32)
+  set(LIBCXX_HERMETIC_STATIC_LIBRARY_DEFAULT ON)
+endif()
 option(LIBCXX_HERMETIC_STATIC_LIBRARY
-  "Do not export any symbols from the static library." OFF)
+  "Do not export any symbols from the static library." ${LIBCXX_HERMETIC_STATIC_LIBRARY_DEFAULT})
 
 #===============================================================================
 # Check option configurations
diff --git a/libcxx/src/CMakeLists.txt b/libcxx/src/CMakeLists.txt
--- a/libcxx/src/CMakeLists.txt
+++ b/libcxx/src/CMakeLists.txt
@@ -300,7 +300,9 @@
       append_flags_if_supported(CXX_STATIC_LIBRARY_FLAGS -fvisibility-global-new-delete-hidden)
     endif()
     target_compile_options(cxx_static PRIVATE ${CXX_STATIC_LIBRARY_FLAGS})
-    target_compile_definitions(cxx_static PRIVATE _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
+    # _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS can be defined in __config_site
+    # too. Define it in the same way here, to avoid redefinition conflicts.
+    target_compile_definitions(cxx_static PRIVATE _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS=)
   endif()
 
   list(APPEND LIBCXX_BUILD_TARGETS "cxx_static")
diff --git a/libcxx/test/libcxx/vendor/clang-cl/static-lib-exports.sh.cpp b/libcxx/test/libcxx/vendor/clang-cl/static-lib-exports.sh.cpp
--- a/libcxx/test/libcxx/vendor/clang-cl/static-lib-exports.sh.cpp
+++ b/libcxx/test/libcxx/vendor/clang-cl/static-lib-exports.sh.cpp
@@ -12,8 +12,3 @@
 // directives in clang-cl builds.
 
 // RUN: llvm-readobj --coff-directives "%{lib}/libc++.lib" | not grep -i "export:" > /dev/null
-
-// It's a known issue, that when building a shared library at the same time
-// as the static library, the generated static library does contain dllexport
-// directives.
-// XFAIL: windows-dll
diff --git a/libcxx/test/libcxx/vendor/mingw/static-lib-exports.sh.cpp b/libcxx/test/libcxx/vendor/mingw/static-lib-exports.sh.cpp
--- a/libcxx/test/libcxx/vendor/mingw/static-lib-exports.sh.cpp
+++ b/libcxx/test/libcxx/vendor/mingw/static-lib-exports.sh.cpp
@@ -12,8 +12,3 @@
 // directives in MinGW builds.
 
 // RUN: llvm-readobj --coff-directives "%{lib}/libc++.a" | not grep -i "export:" > /dev/null
-
-// It's a known issue, that when building a shared library at the same time
-// as the static library, the generated static library does contain dllexport
-// directives.
-// XFAIL: windows-dll
diff --git a/libcxxabi/CMakeLists.txt b/libcxxabi/CMakeLists.txt
--- a/libcxxabi/CMakeLists.txt
+++ b/libcxxabi/CMakeLists.txt
@@ -136,8 +136,12 @@
 set(LIBCXXABI_LIBCXX_INCLUDES "" CACHE PATH
     "Specify path to libc++ includes.")
 
+set(LIBCXXABI_HERMETIC_STATIC_LIBRARY_DEFAULT OFF)
+if (WIN32)
+  set(LIBCXXABI_HERMETIC_STATIC_LIBRARY_DEFAULT ON)
+endif()
 option(LIBCXXABI_HERMETIC_STATIC_LIBRARY
-  "Do not export any symbols from the static library." OFF)
+  "Do not export any symbols from the static library." ${LIBCXXABI_HERMETIC_STATIC_LIBRARY_DEFAULT})
 
 set(LIBCXXABI_TEST_CONFIG "${CMAKE_CURRENT_SOURCE_DIR}/test/lit.site.cfg.in" CACHE STRING
   "The path to the Lit testing configuration to use when running the tests.
@@ -247,25 +251,6 @@
 # it is being built as part of libcxx.
 add_definitions(-D_LIBCPP_BUILDING_LIBRARY)
 
-# Disable DLL annotations on Windows for static builds.
-if (WIN32 AND LIBCXXABI_ENABLE_STATIC AND NOT LIBCXXABI_ENABLE_SHARED)
-  # If LIBCXX_ENABLE_SHARED isn't set (by the user on the cmake command
-  # line or via a cache file), use its expected default value (enabled).
-  if ((LIBCXX_ENABLE_SHARED OR NOT DEFINED LIBCXX_ENABLE_SHARED) AND LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
-    # Building libcxxabi statically, but intending for it to be statically
-    # linked into a shared libcxx; keep dllexport enabled within libcxxabi,
-    # as the symbols will need to be exported from libcxx.
-  else()
-    # Regular static build; disable dllexports.
-    add_definitions(-D_LIBCXXABI_DISABLE_VISIBILITY_ANNOTATIONS)
-    if (NOT LIBCXXABI_HERMETIC_STATIC_LIBRARY)
-      # TODO: Enable this warning message as soon as we're sure this is the solution.
-      # message(WARNING "Implicitly disabling dllexport on Win32 is not supported anymore. Please build with "
-      #                 "LIBCXXABI_HERMETIC_STATIC_LIBRARY=ON instead. This will become an error in LLVM 16.")
-    endif()
-  endif()
-endif()
-
 add_compile_flags_if_supported(-Werror=return-type)
 
 # Get warning flags
diff --git a/libcxxabi/src/CMakeLists.txt b/libcxxabi/src/CMakeLists.txt
--- a/libcxxabi/src/CMakeLists.txt
+++ b/libcxxabi/src/CMakeLists.txt
@@ -248,10 +248,13 @@
   if (LIBCXXABI_ENABLE_NEW_DELETE_DEFINITIONS)
     target_add_compile_flags_if_supported(cxxabi_static_objects PRIVATE -fvisibility-global-new-delete-hidden)
   endif()
+  # _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS can be defined in libcxx's
+  # __config_site too. Define it in the same way here, to avoid redefinition
+  # conflicts.
   target_compile_definitions(cxxabi_static_objects
     PRIVATE
       _LIBCXXABI_DISABLE_VISIBILITY_ANNOTATIONS
-      _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
+      _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS=)
 endif()
 
 if (LIBCXXABI_ENABLE_STATIC)
diff --git a/libunwind/CMakeLists.txt b/libunwind/CMakeLists.txt
--- a/libunwind/CMakeLists.txt
+++ b/libunwind/CMakeLists.txt
@@ -93,8 +93,13 @@
   message(FATAL_ERROR "libunwind CET support is not available for MSVC!")
 endif()
 
+if (WIN32)
+  set(LIBUNWIND_DEFAULT_HIDE_SYMBOLS TRUE)
+else()
+  set(LIBUNWIND_DEFAULT_HIDE_SYMBOLS FALSE)
+endif()
 option(LIBUNWIND_HIDE_SYMBOLS
-  "Do not export any symbols from the static library." OFF)
+  "Do not export any symbols from the static library." ${LIBUNWIND_DEFAULT_HIDE_SYMBOLS})
 
 #===============================================================================
 # Configure System
@@ -304,11 +309,6 @@
   add_definitions(-D_CRT_SECURE_NO_WARNINGS)
 endif()
 
-# Disable DLL annotations on Windows for static builds.
-if (WIN32 AND LIBUNWIND_ENABLE_STATIC AND NOT LIBUNWIND_ENABLE_SHARED)
-  add_definitions(-D_LIBUNWIND_HIDE_SYMBOLS)
-endif()
-
 if (C_SUPPORTS_COMMENT_LIB_PRAGMA)
   if (LIBUNWIND_HAS_DL_LIB)
     add_definitions(-D_LIBUNWIND_LINK_DL_LIB)