Index: libcxxabi/CMakeLists.txt
===================================================================
--- libcxxabi/CMakeLists.txt
+++ libcxxabi/CMakeLists.txt
@@ -156,9 +156,23 @@
   message(FATAL_ERROR "libc++abi must be built as either a shared or static library.")
 endif()
 
-set(LIBCXXABI_LIBCXX_INCLUDES "${LIBCXXABI_LIBCXX_PATH}/include" CACHE PATH
+# TODO: This is a workaround for the fact that Standalone builds can't use
+# targets from the other runtimes (so the cxx-headers target doesn't exist).
+set(LIBCXXABI_LIBCXX_INCLUDES "" CACHE PATH
     "Specify path to libc++ includes.")
-message(STATUS "Libc++abi will be using libc++ includes from ${LIBCXXABI_LIBCXX_INCLUDES}")
+if (LIBCXXABI_STANDALONE_BUILD)
+  if (NOT IS_DIRECTORY ${LIBCXXABI_LIBCXX_INCLUDES})
+    message(FATAL_ERROR
+      "LIBCXXABI_LIBCXX_INCLUDES=${LIBCXXABI_LIBCXX_INCLUDES} is not a valid directory. "
+      "Please provide the path to where the libc++ headers have been installed.")
+  endif()
+  add_library(cxx-headers INTERFACE)
+  if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC" OR "${CMAKE_CXX_SIMULATE_ID}" STREQUAL "MSVC")
+    target_compile_options(cxx-headers INTERFACE /I "${LIBCXXABI_LIBCXX_INCLUDES}")
+  else()
+    target_compile_options(cxx-headers INTERFACE -I "${LIBCXXABI_LIBCXX_INCLUDES}")
+  endif()
+endif()
 
 option(LIBCXXABI_HERMETIC_STATIC_LIBRARY
   "Do not export any symbols from the static library." OFF)
Index: libcxxabi/src/CMakeLists.txt
===================================================================
--- libcxxabi/src/CMakeLists.txt
+++ libcxxabi/src/CMakeLists.txt
@@ -177,7 +177,7 @@
 # Build the shared library.
 if (LIBCXXABI_ENABLE_SHARED)
   add_library(cxxabi_shared SHARED ${LIBCXXABI_SOURCES} ${LIBCXXABI_HEADERS})
-  target_link_libraries(cxxabi_shared PRIVATE ${LIBCXXABI_SHARED_LIBRARIES} ${LIBCXXABI_LIBRARIES})
+  target_link_libraries(cxxabi_shared PRIVATE cxx-headers ${LIBCXXABI_SHARED_LIBRARIES} ${LIBCXXABI_LIBRARIES})
   if (TARGET pstl::ParallelSTL)
     target_link_libraries(cxxabi_shared PUBLIC pstl::ParallelSTL)
   endif()
@@ -244,7 +244,7 @@
 # Build the static library.
 if (LIBCXXABI_ENABLE_STATIC)
   add_library(cxxabi_static STATIC ${LIBCXXABI_SOURCES} ${LIBCXXABI_HEADERS})
-  target_link_libraries(cxxabi_static PRIVATE ${LIBCXXABI_STATIC_LIBRARIES} ${LIBCXXABI_LIBRARIES})
+  target_link_libraries(cxxabi_static PRIVATE cxx-headers ${LIBCXXABI_STATIC_LIBRARIES} ${LIBCXXABI_LIBRARIES})
   if (TARGET pstl::ParallelSTL)
     target_link_libraries(cxxabi_static PUBLIC pstl::ParallelSTL)
   endif()