diff --git a/libcxx/cmake/caches/Generic-cxx20.cmake b/libcxx/cmake/caches/Generic-cxx20.cmake
index 3c44fdaf0e4253..641c131a737b18 100644
--- a/libcxx/cmake/caches/Generic-cxx20.cmake
+++ b/libcxx/cmake/caches/Generic-cxx20.cmake
@@ -1,2 +1,3 @@
+set(LIBCXX_INSTALL_MODULES ON CACHE BOOL "") # TODO MODULES Remove when enabled automatically.
 set(LIBCXX_TEST_PARAMS "std=c++20" CACHE STRING "")
 set(LIBCXXABI_TEST_PARAMS "${LIBCXX_TEST_PARAMS}" CACHE STRING "")
diff --git a/libcxx/cmake/caches/Generic-cxx23.cmake b/libcxx/cmake/caches/Generic-cxx23.cmake
index bf88abf56ca6a4..f5409e4652e429 100644
--- a/libcxx/cmake/caches/Generic-cxx23.cmake
+++ b/libcxx/cmake/caches/Generic-cxx23.cmake
@@ -1,2 +1,3 @@
+set(LIBCXX_INSTALL_MODULES ON CACHE BOOL "") # TODO MODULES Remove when enabled automatically.
 set(LIBCXX_TEST_PARAMS "std=c++23" CACHE STRING "")
 set(LIBCXXABI_TEST_PARAMS "${LIBCXX_TEST_PARAMS}" CACHE STRING "")
diff --git a/libcxx/docs/ReleaseNotes/18.rst b/libcxx/docs/ReleaseNotes/18.rst
index 5eb47221693229..1b04702f4ae6b0 100644
--- a/libcxx/docs/ReleaseNotes/18.rst
+++ b/libcxx/docs/ReleaseNotes/18.rst
@@ -98,7 +98,7 @@ Improvements and New Features
   configuring CMake with ``-DLIBCXX_INSTALL_MODULES=ON``. The installation
   directory can be configured with the CMake option
   ``-DLIBCXX_INSTALL_MODULE_DIR=<path>``. The default location is
-  ``share/libc++/v1`` in the same prefix as the ``include`` directory.
+  ``${PREFIX}/share/libc++/v1``.
 
 
 Deprecations and Removals
diff --git a/libcxx/modules/CMakeLists.txt b/libcxx/modules/CMakeLists.txt
index 186a2f17a89e52..9b9e670d73d81c 100644
--- a/libcxx/modules/CMakeLists.txt
+++ b/libcxx/modules/CMakeLists.txt
@@ -183,6 +183,7 @@ add_custom_target(generate-cxx-modules
     ${_all_modules}
 )
 
+# Configure the modules manifest.
 # Use the relative path between the installation and the module in the json
 # file. This allows moving the entire installation to a different location.
 file(RELATIVE_PATH LIBCXX_MODULE_RELATIVE_PATH
@@ -232,6 +233,6 @@ if (LIBCXX_INSTALL_MODULE_INTERFACE_UNIT_SOURCES)
                               -DCMAKE_INSTALL_COMPONENT=cxx-modules
                               -P "${CMAKE_BINARY_DIR}/cmake_install.cmake")
     # Stripping is a no-op for modules
-    add_custom_target(install-cxx-modules-stripped DEPENDS install-cxx-headers)
+    add_custom_target(install-cxx-modules-stripped DEPENDS install-cxx-modules)
   endif()
 endif()
diff --git a/libcxx/src/CMakeLists.txt b/libcxx/src/CMakeLists.txt
index a9edb98e1adba5..ff65c2a26124b3 100644
--- a/libcxx/src/CMakeLists.txt
+++ b/libcxx/src/CMakeLists.txt
@@ -400,12 +400,13 @@ if (NOT CMAKE_CONFIGURATION_TYPES)
       set(header_install_target install-cxx-headers)
     endif()
     if(LIBCXX_INSTALL_MODULE_INTERFACE_UNIT_SOURCES)
-      set(header_install_target install-cxx-modules)
+      set(module_install_target install-cxx-modules)
     endif()
     add_custom_target(install-cxx
                       DEPENDS ${lib_install_target}
                               cxx_experimental
                               ${header_install_target}
+                              ${module_install_target}
                       COMMAND "${CMAKE_COMMAND}"
                       -DCMAKE_INSTALL_COMPONENT=cxx
                       -P "${LIBCXX_BINARY_DIR}/cmake_install.cmake")
@@ -413,6 +414,7 @@ if (NOT CMAKE_CONFIGURATION_TYPES)
                       DEPENDS ${lib_install_target}
                               cxx_experimental
                               ${header_install_target}
+                              ${module_install_target}
                       COMMAND "${CMAKE_COMMAND}"
                       -DCMAKE_INSTALL_COMPONENT=cxx
                       -DCMAKE_INSTALL_DO_STRIP=1