diff --git a/Help/prop_tgt/OBJC_STANDARD.rst b/Help/prop_tgt/OBJC_STANDARD.rst
index 0609239f5..a3c565313 100644
--- a/Help/prop_tgt/OBJC_STANDARD.rst
+++ b/Help/prop_tgt/OBJC_STANDARD.rst
@@ -20,6 +20,16 @@ Supported values are:
 ``11``
   Objective C11
 
+``17``
+  .. versionadded:: 3.21
+
+  Objective C17
+
+``23``
+  .. versionadded:: 3.21
+
+  Objective C23
+
 If the value requested does not result in a compile flag being added for
 the compiler in use, a previous standard flag will be added instead.  This
 means that using:
diff --git a/Help/release/3.28.rst b/Help/release/3.28.rst
index 9e2a422fa..77f03f63f 100644
--- a/Help/release/3.28.rst
+++ b/Help/release/3.28.rst
@@ -213,3 +213,9 @@ Changes made since CMake 3.28.0 include the following.
 
 * Apple visionOS support has been updated for the official Xcode 15.2
   release of the  ``xros`` and ``xrsimulator`` SDKs.
+
+3.28.5
+------
+
+* This version made no changes to documented features or interfaces.
+  Some implementation updates were made to C++ modules support.
diff --git a/Help/release/3.29.rst b/Help/release/3.29.rst
index 302bdf4e6..35f6d396e 100644
--- a/Help/release/3.29.rst
+++ b/Help/release/3.29.rst
@@ -212,9 +212,9 @@ Changes made since CMake 3.29.0 include the following.
   :prop_tgt:`LINKER_TYPE` target property now work with compilers
   for the ``Swift`` language.
 
-3.29.2
-------
+3.29.2, 3.29.3
+--------------
 
-* This version made no changes to documented features or interfaces.
+* These versions made no changes to documented features or interfaces.
   Some implementation updates were made to support ecosystem changes
   and/or fix regressions.
diff --git a/Modules/CMakeDetermineCompilerABI.cmake b/Modules/CMakeDetermineCompilerABI.cmake
index 012a87caf..87218d207 100644
--- a/Modules/CMakeDetermineCompilerABI.cmake
+++ b/Modules/CMakeDetermineCompilerABI.cmake
@@ -39,6 +39,9 @@ function(CMAKE_DETERMINE_COMPILER_ABI lang src)
       endif()
       set(CMAKE_${lang}_RUNTIME_LIBRARY "Static")
     endif()
+    if(lang STREQUAL "CXX")
+      set(CMAKE_${lang}_SCAN_FOR_MODULES OFF)
+    endif()
     if(NOT "x${CMAKE_${lang}_COMPILER_ID}" STREQUAL "xMSVC")
       # Avoid adding our own platform standard libraries for compilers
       # from which we might detect implicit link libraries.
diff --git a/Modules/CMakePackageConfigHelpers.cmake b/Modules/CMakePackageConfigHelpers.cmake
index dfe1ec7dc..9fa30b6b7 100644
--- a/Modules/CMakePackageConfigHelpers.cmake
+++ b/Modules/CMakePackageConfigHelpers.cmake
@@ -5,7 +5,7 @@
 CMakePackageConfigHelpers
 -------------------------
 
-Helpers functions for creating config files that can be included by other
+Helper functions for creating config files that can be included by other
 projects to find and use a package.
 
 Generating a Package Configuration File
@@ -26,11 +26,11 @@ Generating a Package Configuration File
 ``configure_package_config_file()`` should be used instead of the plain
 :command:`configure_file()` command when creating the ``<PackageName>Config.cmake``
 or ``<PackageName>-config.cmake`` file for installing a project or library.
-It helps making the resulting package relocatable by avoiding hardcoded paths
-in the installed ``Config.cmake`` file.
+It helps make the resulting package relocatable by avoiding hardcoded paths
+in the installed ``<PackageName>Config.cmake`` file.
 
 In a ``FooConfig.cmake`` file there may be code like this to make the install
-destinations know to the using project:
+destinations known to the using project:
 
 .. code-block:: cmake
 
@@ -40,27 +40,25 @@ destinations know to the using project:
    #...logic to determine installedPrefix from the own location...
    set(FOO_CONFIG_DIR  "${installedPrefix}/@CONFIG_INSTALL_DIR@" )
 
-All 4 options shown above are not sufficient, since the first 3 hardcode the
-absolute directory locations, and the 4th case works only if the logic to
+All four options shown above are not sufficient  The first three hardcode the
+absolute directory locations.  The fourth case works only if the logic to
 determine the ``installedPrefix`` is correct, and if ``CONFIG_INSTALL_DIR``
 contains a relative path, which in general cannot be guaranteed.  This has the
 effect that the resulting ``FooConfig.cmake`` file would work poorly under
-Windows and OSX, where users are used to choose the install location of a
+Windows and macOS, where users are used to choosing the install location of a
 binary package at install time, independent from how
 :variable:`CMAKE_INSTALL_PREFIX` was set at build/cmake time.
 
-Using ``configure_package_config_file`` helps.  If used correctly, it makes
+Using ``configure_package_config_file()`` helps.  If used correctly, it makes
 the resulting ``FooConfig.cmake`` file relocatable.  Usage:
 
-1. write a ``FooConfig.cmake.in`` file as you are used to
-2. insert a line containing only the string ``@PACKAGE_INIT@``
-3. instead of ``set(FOO_DIR "@SOME_INSTALL_DIR@")``, use
+1. Write a ``FooConfig.cmake.in`` file as you are used to.
+2. Insert a line at the top containing only the string ``@PACKAGE_INIT@``.
+3. Instead of ``set(FOO_DIR "@SOME_INSTALL_DIR@")``, use
    ``set(FOO_DIR "@PACKAGE_SOME_INSTALL_DIR@")`` (this must be after the
-   ``@PACKAGE_INIT@`` line)
-4. instead of using the normal :command:`configure_file()`, use
-   ``configure_package_config_file()``
-
-
+   ``@PACKAGE_INIT@`` line).
+4. Instead of using the normal :command:`configure_file()` command, use
+   ``configure_package_config_file()``.
 
 The ``<input>`` and ``<output>`` arguments are the input and output file, the
 same way as in :command:`configure_file()`.
@@ -70,48 +68,47 @@ the ``FooConfig.cmake`` file will be installed to.  This path can either be
 absolute, or relative to the ``INSTALL_PREFIX`` path.
 
 The variables ``<var1>`` to ``<varN>`` given as ``PATH_VARS`` are the
-variables which contain install destinations.  For each of them the macro will
+variables which contain install destinations.  For each of them, the macro will
 create a helper variable ``PACKAGE_<var...>``.  These helper variables must be
 used in the ``FooConfig.cmake.in`` file for setting the installed location.
-They are calculated by ``configure_package_config_file`` so that they are
+They are calculated by ``configure_package_config_file()`` so that they are
 always relative to the installed location of the package.  This works both for
-relative and also for absolute locations.  For absolute locations it works
+relative and also for absolute locations.  For absolute locations, it works
 only if the absolute location is a subdirectory of ``INSTALL_PREFIX``.
 
 .. versionadded:: 3.1
-  If the ``INSTALL_PREFIX`` argument is passed, this is used as base path to
+  If the ``INSTALL_PREFIX`` argument is passed, this is used as the base path to
   calculate all the relative paths.  The ``<path>`` argument must be an absolute
   path.  If this argument is not passed, the :variable:`CMAKE_INSTALL_PREFIX`
   variable will be used instead.  The default value is good when generating a
-  FooConfig.cmake file to use your package from the install tree.  When
-  generating a FooConfig.cmake file to use your package from the build tree this
-  option should be used.
+  ``FooConfig.cmake`` file to use your package from the install tree.  When
+  generating a ``FooConfig.cmake`` file to use your package from the build tree,
+  this option should be used.
 
-By default ``configure_package_config_file`` also generates two helper macros,
-``set_and_check()`` and ``check_required_components()`` into the
+By default, ``configure_package_config_file()`` also generates two helper
+macros, ``set_and_check()`` and ``check_required_components()``, into the
 ``FooConfig.cmake`` file.
 
-``set_and_check()`` should be used instead of the normal ``set()`` command for
-setting directories and file locations.  Additionally to setting the variable
-it also checks that the referenced file or directory actually exists and fails
-with a ``FATAL_ERROR`` otherwise.  This makes sure that the created
+``set_and_check()`` should be used instead of the normal :command:`set` command
+for setting directories and file locations.  In addition to setting the
+variable, it also checks that the referenced file or directory actually exists
+and fails with a fatal error if it doesn't.  This ensures that the generated
 ``FooConfig.cmake`` file does not contain wrong references.
-When using the ``NO_SET_AND_CHECK_MACRO``, this macro is not generated
-into the ``FooConfig.cmake`` file.
+Add the ``NO_SET_AND_CHECK_MACRO`` option to prevent the generation of the
+``set_and_check()`` macro in the ``FooConfig.cmake`` file.
 
 ``check_required_components(<PackageName>)`` should be called at the end of
 the ``FooConfig.cmake`` file. This macro checks whether all requested,
-non-optional components have been found, and if this is not the case, sets
-the ``Foo_FOUND`` variable to ``FALSE``, so that the package is considered to
+non-optional components have been found, and if this is not the case, it sets
+the ``Foo_FOUND`` variable to ``FALSE`` so that the package is considered to
 be not found.  It does that by testing the ``Foo_<Component>_FOUND``
 variables for all requested required components.  This macro should be
 called even if the package doesn't provide any components to make sure
-users are not specifying components erroneously.  When using the
-``NO_CHECK_REQUIRED_COMPONENTS_MACRO`` option, this macro is not generated
-into the ``FooConfig.cmake`` file.
+users are not specifying components erroneously.  Add the
+``NO_CHECK_REQUIRED_COMPONENTS_MACRO`` option to prevent the generation of the
+``check_required_components()`` macro in the ``FooConfig.cmake`` file.
 
-For an example see below the documentation for
-:command:`write_basic_package_version_file()`.
+See also :ref:`CMakePackageConfigHelpers Examples`.
 
 Generating a Package Version File
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -126,11 +123,11 @@ Generating a Package Version File
      [ARCH_INDEPENDENT] )
 
 
-Writes a file for use as ``<PackageName>ConfigVersion.cmake`` file to
+Writes a file for use as a ``<PackageName>ConfigVersion.cmake`` file to
 ``<filename>``.  See the documentation of :command:`find_package()` for
-details on this.
+details on such files.
 
-``<filename>`` is the output filename, it should be in the build tree.
+``<filename>`` is the output filename, which should be in the build tree.
 ``<major.minor.patch>`` is the version number of the project to be installed.
 
 If no ``VERSION`` is given, the :variable:`PROJECT_VERSION` variable is used.
@@ -153,9 +150,9 @@ the requested version matches exactly its own version number (not considering
 the tweak version).  For example, version 1.2.3 of a package is only
 considered compatible to requested version 1.2.3.  This mode is for packages
 without compatibility guarantees.
-If your project has more elaborated version matching rules, you will need to
-write your own custom ``ConfigVersion.cmake`` file instead of using this
-macro.
+If your project has more elaborate version matching rules, you will need to
+write your own custom ``<PackageName>ConfigVersion.cmake`` file instead of
+using this macro.
 
 .. versionadded:: 3.11
   The ``SameMinorVersion`` compatibility mode.
@@ -170,13 +167,13 @@ macro.
   unless ``ARCH_INDEPENDENT`` is given, in which case the package is considered
   compatible on any architecture.
 
-.. note:: ``ARCH_INDEPENDENT`` is intended for header-only libraries or similar
-  packages with no binaries.
+  .. note:: ``ARCH_INDEPENDENT`` is intended for header-only libraries or
+    similar packages with no binaries.
 
 .. versionadded:: 3.19
   The version file generated by ``AnyNewerVersion``, ``SameMajorVersion`` and
-  ``SameMinorVersion`` arguments of ``COMPATIBILITY`` handle the version range
-  if any is specified (see :command:`find_package` command for the details).
+  ``SameMinorVersion`` arguments of ``COMPATIBILITY`` handle the version range,
+  if one is specified (see :command:`find_package` command for the details).
   ``ExactVersion`` mode is incompatible with version ranges and will display an
   author warning if one is specified.
 
@@ -184,8 +181,9 @@ Internally, this macro executes :command:`configure_file()` to create the
 resulting version file.  Depending on the ``COMPATIBILITY``, the corresponding
 ``BasicConfigVersion-<COMPATIBILITY>.cmake.in`` file is used.
 Please note that these files are internal to CMake and you should not call
-:command:`configure_file()` on them yourself, but they can be used as starting
-point to create more sophisticated custom ``ConfigVersion.cmake`` files.
+:command:`configure_file()` on them yourself, but they can be used as a starting
+point to create more sophisticated custom ``<PackageName>ConfigVersion.cmake``
+files.
 
 Generating an Apple Platform Selection File
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -268,6 +266,9 @@ Generating an Apple Platform Selection File
   consider the platform to be unsupported.  The behavior is determined
   by the ``ERROR_VARIABLE`` option.
 
+Generating an Apple Architecture Selection File
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
 .. command:: generate_apple_architecture_selection_file
 
   .. versionadded:: 3.29
@@ -328,15 +329,16 @@ Generating an Apple Platform Selection File
     information to pretend the package was not found.  If this option
     is not given, the default behavior is to issue a fatal error.
 
+.. _`CMakePackageConfigHelpers Examples`:
+
 Example Generating Package Files
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-Example using both :command:`configure_package_config_file` and
-``write_basic_package_version_file()``:
-
-``CMakeLists.txt``:
+Example using both the :command:`configure_package_config_file` and
+:command:`write_basic_package_version_file()` commands:
 
 .. code-block:: cmake
+   :caption: ``CMakeLists.txt``
 
    include(GNUInstallDirs)
    set(INCLUDE_INSTALL_DIR ${CMAKE_INSTALL_INCLUDEDIR}/Foo
@@ -357,9 +359,9 @@ Example using both :command:`configure_package_config_file` and
                  ${CMAKE_CURRENT_BINARY_DIR}/FooConfigVersion.cmake
            DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/Foo )
 
-``FooConfig.cmake.in``:
-
-::
+.. code-block:: cmake
+   :caption: ``FooConfig.cmake.in``
+   :force:
 
    set(FOO_VERSION x.y.z)
    ...
@@ -597,8 +599,15 @@ function(generate_apple_architecture_selection_file _output_file)
       )
   endif()
   string(APPEND _branch_code
-    "endif()\n"
+    "endif()\n\n"
+    "set(_cmake_apple_archs \"\${CMAKE_OSX_ARCHITECTURES}\")\n"
     )
+  if(NOT "${_gasf_UNIVERSAL_ARCHITECTURES}" STREQUAL "")
+    string(APPEND _branch_code "list(REMOVE_ITEM _cmake_apple_archs ${_gasf_UNIVERSAL_ARCHITECTURES})\n")
+  endif()
+  string(APPEND _branch_code "\n")
+
+  set(maybe_else "")
 
   foreach(pair IN ZIP_LISTS _gasf_SINGLE_ARCHITECTURES _gasf_SINGLE_ARCHITECTURE_INCLUDE_FILES)
     set(arch "${pair_0}")
@@ -607,40 +616,45 @@ function(generate_apple_architecture_selection_file _output_file)
       string(PREPEND config_file [[${PACKAGE_PREFIX_DIR}/]])
     endif()
     string(APPEND _branch_code
-      "\n"
-      "if(CMAKE_OSX_ARCHITECTURES STREQUAL \"${arch}\")\n"
+      "${maybe_else}if(CMAKE_OSX_ARCHITECTURES STREQUAL \"${arch}\")\n"
       "  include(\"${config_file}\")\n"
-      "  return()\n"
-      "endif()\n"
       )
+    set(maybe_else else)
   endforeach()
 
   if(_gasf_UNIVERSAL_ARCHITECTURES AND _gasf_UNIVERSAL_INCLUDE_FILE)
-    string(JOIN " " universal_archs "${_gasf_UNIVERSAL_ARCHITECTURES}")
     set(config_file "${_gasf_UNIVERSAL_INCLUDE_FILE}")
     if(NOT IS_ABSOLUTE "${config_file}")
       string(PREPEND config_file [[${PACKAGE_PREFIX_DIR}/]])
     endif()
     string(APPEND _branch_code
-      "\n"
-      "set(_cmake_apple_archs \"\${CMAKE_OSX_ARCHITECTURES}\")\n"
-      "list(REMOVE_ITEM _cmake_apple_archs ${universal_archs})\n"
-      "if(NOT _cmake_apple_archs)\n"
+      "${maybe_else}if(NOT _cmake_apple_archs)\n"
       "  include(\"${config_file}\")\n"
-      "  return()\n"
-      "endif()\n"
       )
+    set(maybe_else else)
   elseif(_gasf_UNIVERSAL_ARCHITECTURES)
     message(FATAL_ERROR "UNIVERSAL_INCLUDE_FILE requires UNIVERSAL_ARCHITECTURES")
   elseif(_gasf_UNIVERSAL_INCLUDE_FILE)
     message(FATAL_ERROR "UNIVERSAL_ARCHITECTURES requires UNIVERSAL_INCLUDE_FILE")
   endif()
 
-  string(APPEND _branch_code "\n")
+  if(maybe_else)
+    string(APPEND _branch_code "else()\n")
+    set(_indent "  ")
+  else()
+    set(_indent "")
+  endif()
   if(_gasf_ERROR_VARIABLE)
-    string(APPEND _branch_code "set(\"${_gasf_ERROR_VARIABLE}\" \"Architecture not supported\")")
+    string(APPEND _branch_code
+      "${_indent}set(\"${_gasf_ERROR_VARIABLE}\" \"Architecture not supported\")\n"
+      )
   else()
-    string(APPEND _branch_code "message(FATAL_ERROR \"Architecture not supported\")")
+    string(APPEND _branch_code
+      "${_indent}message(FATAL_ERROR \"Architecture not supported\")\n"
+      )
+  endif()
+  if(maybe_else)
+    string(APPEND _branch_code "endif()\n")
   endif()
 
   configure_package_config_file("${CMAKE_CURRENT_FUNCTION_LIST_DIR}/Internal/AppleArchitectureSelection.cmake.in" "${_output_file}"
diff --git a/Modules/CMakeTestCXXCompiler.cmake b/Modules/CMakeTestCXXCompiler.cmake
index e640ff9b3..a9fbb26ca 100644
--- a/Modules/CMakeTestCXXCompiler.cmake
+++ b/Modules/CMakeTestCXXCompiler.cmake
@@ -37,6 +37,13 @@ endif()
 # any makefiles or projects.
 if(NOT CMAKE_CXX_COMPILER_WORKS)
   PrintTestCompilerStatus("CXX")
+  # FIXME: Use a block() to isolate the variables we set/unset here.
+  if(DEFINED CMAKE_CXX_SCAN_FOR_MODULES)
+    set(__CMAKE_SAVED_CXX_SCAN_FOR_MODULES "${CMAKE_CXX_SCAN_FOR_MODULES}")
+  else()
+    unset(__CMAKE_SAVED_CXX_SCAN_FOR_MODULES)
+  endif()
+  set(CMAKE_CXX_SCAN_FOR_MODULES OFF)
   __TestCompiler_setTryCompileTargetType()
   string(CONCAT __TestCompiler_testCXXCompilerSource
     "#ifndef __cplusplus\n"
@@ -49,6 +56,12 @@ if(NOT CMAKE_CXX_COMPILER_WORKS)
   try_compile(CMAKE_CXX_COMPILER_WORKS
     SOURCE_FROM_VAR testCXXCompiler.cxx __TestCompiler_testCXXCompilerSource
     OUTPUT_VARIABLE __CMAKE_CXX_COMPILER_OUTPUT)
+  if(DEFINED __CMAKE_SAVED_CXX_SCAN_FOR_MODULES)
+    set(CMAKE_CXX_SCAN_FOR_MODULES "${__CMAKE_SAVED_CXX_SCAN_FOR_MODULES}")
+    unset(__CMAKE_SAVED_CXX_SCAN_FOR_MODULES)
+  else()
+    unset(CMAKE_CXX_SCAN_FOR_MODULES)
+  endif()
   unset(__TestCompiler_testCXXCompilerSource)
   # Move result from cache to normal variable.
   set(CMAKE_CXX_COMPILER_WORKS ${CMAKE_CXX_COMPILER_WORKS})
diff --git a/Modules/FindBoost.cmake b/Modules/FindBoost.cmake
index 248ea8b63..54d1a78a5 100644
--- a/Modules/FindBoost.cmake
+++ b/Modules/FindBoost.cmake
@@ -1394,7 +1394,7 @@ function(_Boost_COMPONENT_DEPENDENCIES component _ret)
       set(_Boost_THREAD_DEPENDENCIES chrono atomic)
       set(_Boost_WAVE_DEPENDENCIES filesystem serialization thread chrono atomic)
       set(_Boost_WSERIALIZATION_DEPENDENCIES serialization)
-      if(Boost_VERSION_STRING VERSION_GREATER_EQUAL 1.85.0 AND NOT Boost_NO_WARN_NEW_VERSIONS)
+      if(Boost_VERSION_STRING VERSION_GREATER_EQUAL 1.86.0 AND NOT Boost_NO_WARN_NEW_VERSIONS)
         message(WARNING "New Boost version may have incorrect or missing dependencies and imported targets")
       endif()
     endif()
@@ -1669,7 +1669,7 @@ else()
   # _Boost_COMPONENT_HEADERS.  See the instructions at the top of
   # _Boost_COMPONENT_DEPENDENCIES.
   set(_Boost_KNOWN_VERSIONS ${Boost_ADDITIONAL_VERSIONS}
-    "1.84.0" "1.84"
+    "1.85.0" "1.85" "1.84.0" "1.84"
     "1.83.0" "1.83" "1.82.0" "1.82" "1.81.0" "1.81" "1.80.0" "1.80" "1.79.0" "1.79"
     "1.78.0" "1.78" "1.77.0" "1.77" "1.76.0" "1.76" "1.75.0" "1.75" "1.74.0" "1.74"
     "1.73.0" "1.73" "1.72.0" "1.72" "1.71.0" "1.71" "1.70.0" "1.70" "1.69.0" "1.69"
diff --git a/Modules/FindHDF5.cmake b/Modules/FindHDF5.cmake
index a44c6f99b..cc6186f33 100644
--- a/Modules/FindHDF5.cmake
+++ b/Modules/FindHDF5.cmake
@@ -987,7 +987,7 @@ if( NOT HDF5_FOUND )
                 HDF5_VERSION_DEFINE
                 REGEX "^[ \t]*#[ \t]*define[ \t]+H5_VERSION[ \t]+" )
             if( "${HDF5_VERSION_DEFINE}" MATCHES
-                "H5_VERSION[ \t]+\"([0-9]+\\.[0-9]+\\.[0-9]+)(-patch([0-9]+))?\"" )
+                "H5_VERSION[ \t]+\"([0-9\\.]+)(-patch([0-9]+))?\"" )
                 set( HDF5_VERSION "${CMAKE_MATCH_1}" )
                 if( CMAKE_MATCH_3 )
                   set( HDF5_VERSION ${HDF5_VERSION}.${CMAKE_MATCH_3})
diff --git a/Modules/Internal/AppleArchitectureSelection.cmake.in b/Modules/Internal/AppleArchitectureSelection.cmake.in
index b7315b68a..0c3a3a24b 100644
--- a/Modules/Internal/AppleArchitectureSelection.cmake.in
+++ b/Modules/Internal/AppleArchitectureSelection.cmake.in
@@ -1,2 +1,23 @@
+# Save this now so we can restore it before returning
+if(NOT DEFINED PACKAGE_PREFIX_DIR)
+  list(APPEND _gasf_PACKAGE_PREFIX_DIR "<__CMAKE_UNDEFINED__>")
+elseif("${PACKAGE_PREFIX_DIR}" STREQUAL "")
+  list(APPEND _gasf_PACKAGE_PREFIX_DIR "<__CMAKE_EMPTY__>")
+else()
+  list(APPEND _gasf_PACKAGE_PREFIX_DIR "${PACKAGE_PREFIX_DIR}")
+endif()
+
 @PACKAGE_INIT@
 @_branch_code@
+
+# Restore PACKAGE_PREFIX_DIR
+list(LENGTH _gasf_PACKAGE_PREFIX_DIR _gasf_tmp)
+math(EXPR _gasf_tmp "${_gasf_tmp} - 1")
+list(GET _gasf_PACKAGE_PREFIX_DIR ${_gasf_tmp} PACKAGE_PREFIX_DIR)
+list(REMOVE_AT _gasf_PACKAGE_PREFIX_DIR ${_gasf_tmp})
+unset(_gasf_tmp)
+if("${PACKAGE_PREFIX_DIR}" STREQUAL "<__CMAKE_UNDEFINED__>")
+  unset(PACKAGE_PREFIX_DIR)
+elseif("${PACKAGE_PREFIX_DIR}" STREQUAL "<__CMAKE_EMPTY__>")
+  set(PACKAGE_PREFIX_DIR "")
+endif()
diff --git a/Modules/Internal/ApplePlatformSelection.cmake.in b/Modules/Internal/ApplePlatformSelection.cmake.in
index 6c03ab6a7..c07f139a8 100644
--- a/Modules/Internal/ApplePlatformSelection.cmake.in
+++ b/Modules/Internal/ApplePlatformSelection.cmake.in
@@ -1,3 +1,12 @@
+# Save this now so we can restore it before returning
+if(NOT DEFINED PACKAGE_PREFIX_DIR)
+  list(APPEND _gpsf_PACKAGE_PREFIX_DIR "<__CMAKE_UNDEFINED__>")
+elseif("${PACKAGE_PREFIX_DIR}" STREQUAL "")
+  list(APPEND _gpsf_PACKAGE_PREFIX_DIR "<__CMAKE_EMPTY__>")
+else()
+  list(APPEND _gpsf_PACKAGE_PREFIX_DIR "${PACKAGE_PREFIX_DIR}")
+endif()
+
 @PACKAGE_INIT@
 
 string(TOLOWER "${CMAKE_OSX_SYSROOT}" _CMAKE_OSX_SYSROOT_LOWER)
@@ -23,3 +32,15 @@ elseif(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
 else()
   @_branch_ELSE@
 endif()
+
+# Restore PACKAGE_PREFIX_DIR
+list(LENGTH _gpsf_PACKAGE_PREFIX_DIR _gpsf_tmp)
+math(EXPR _gpsf_tmp "${_gpsf_tmp} - 1")
+list(GET _gpsf_PACKAGE_PREFIX_DIR ${_gpsf_tmp} PACKAGE_PREFIX_DIR)
+list(REMOVE_AT _gpsf_PACKAGE_PREFIX_DIR ${_gpsf_tmp})
+unset(_gpsf_tmp)
+if("${PACKAGE_PREFIX_DIR}" STREQUAL "<__CMAKE_UNDEFINED__>")
+  unset(PACKAGE_PREFIX_DIR)
+elseif("${PACKAGE_PREFIX_DIR}" STREQUAL "<__CMAKE_EMPTY__>")
+  set(PACKAGE_PREFIX_DIR "")
+endif()
diff --git a/Source/CMakeVersion.cmake b/Source/CMakeVersion.cmake
index a906ee091..6cacae7b9 100644
--- a/Source/CMakeVersion.cmake
+++ b/Source/CMakeVersion.cmake
@@ -1,7 +1,7 @@
 # CMake version number components.
 set(CMake_VERSION_MAJOR 3)
 set(CMake_VERSION_MINOR 29)
-set(CMake_VERSION_PATCH 2)
+set(CMake_VERSION_PATCH 3)
 #set(CMake_VERSION_RC 0)
 set(CMake_VERSION_IS_DIRTY 0)
 
@@ -21,7 +21,7 @@ endif()
 
 if(NOT CMake_VERSION_NO_GIT)
   # If this source was exported by 'git archive', use its commit info.
-  set(git_info [==[d3190d6a73 CMake 3.29.2]==])
+  set(git_info [==[b39fb31bf4 CMake 3.29.3]==])
 
   # Otherwise, try to identify the current development source version.
   if(NOT git_info MATCHES "^([0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]?[0-9a-f]?)[0-9a-f]* "
diff --git a/Source/cmDyndepCollation.cxx b/Source/cmDyndepCollation.cxx
index ed4762b41..bfe3a75ea 100644
--- a/Source/cmDyndepCollation.cxx
+++ b/Source/cmDyndepCollation.cxx
@@ -207,6 +207,7 @@ Json::Value CollationInformationExports(cmGeneratorTarget const* gt)
 {
   Json::Value tdi_exports = Json::arrayValue;
   std::string export_name = gt->GetExportName();
+  std::string fs_export_name = gt->GetFilesystemExportName();
 
   auto const& all_install_exports = gt->GetGlobalGenerator()->GetExportSets();
   for (auto const& exp : all_install_exports) {
@@ -232,6 +233,7 @@ Json::Value CollationInformationExports(cmGeneratorTarget const* gt)
 
       tdi_export_info["namespace"] = ns;
       tdi_export_info["export-name"] = export_name;
+      tdi_export_info["filesystem-export-name"] = fs_export_name;
       tdi_export_info["destination"] = dest;
       tdi_export_info["cxx-module-info-dir"] = cxxm_dir;
       tdi_export_info["export-prefix"] = export_prefix;
@@ -241,8 +243,10 @@ Json::Value CollationInformationExports(cmGeneratorTarget const* gt)
     }
   }
 
-  auto const& all_build_exports = gt->Makefile->GetExportBuildFileGenerators();
-  for (auto const& exp : all_build_exports) {
+  auto const& all_build_exports =
+    gt->GetGlobalGenerator()->GetBuildExportSets();
+  for (auto const& exp_entry : all_build_exports) {
+    auto const* exp = exp_entry.second;
     std::vector<cmExportBuildFileGenerator::TargetExport> targets;
     exp->GetTargets(targets);
 
@@ -268,6 +272,7 @@ Json::Value CollationInformationExports(cmGeneratorTarget const* gt)
 
     tdi_export_info["namespace"] = ns;
     tdi_export_info["export-name"] = export_name;
+    tdi_export_info["filesystem-export-name"] = fs_export_name;
     tdi_export_info["destination"] = dest;
     tdi_export_info["cxx-module-info-dir"] = cxxm_dir;
     tdi_export_info["export-prefix"] = export_prefix;
@@ -315,6 +320,7 @@ struct CxxModuleBmiInstall
 struct CxxModuleExport
 {
   std::string Name;
+  std::string FilesystemName;
   std::string Destination;
   std::string Prefix;
   std::string CxxModuleInfoDir;
@@ -352,6 +358,7 @@ cmDyndepCollation::ParseExportInfo(Json::Value const& tdi)
       CxxModuleExport exp;
       exp.Install = tdi_export["install"].asBool();
       exp.Name = tdi_export["export-name"].asString();
+      exp.FilesystemName = tdi_export["filesystem-export-name"].asString();
       exp.Destination = tdi_export["destination"].asString();
       exp.Prefix = tdi_export["export-prefix"].asString();
       exp.CxxModuleInfoDir = tdi_export["cxx-module-info-dir"].asString();
@@ -426,8 +433,9 @@ bool cmDyndepCollation::WriteDyndepMetadata(
 
     std::string const export_dir =
       cmStrCat(exp.Prefix, '/', exp.CxxModuleInfoDir, '/');
-    std::string const property_file_path = cmStrCat(
-      export_dir, "target-", exp.Name, '-', export_info.Config, ".cmake");
+    std::string const property_file_path =
+      cmStrCat(export_dir, "target-", exp.FilesystemName, '-',
+               export_info.Config, ".cmake");
     properties = cm::make_unique<cmGeneratedFileStream>(property_file_path);
 
     // Set up the preamble.
diff --git a/Source/cmExportBuildFileGenerator.cxx b/Source/cmExportBuildFileGenerator.cxx
index 81e3d546c..2345d64b9 100644
--- a/Source/cmExportBuildFileGenerator.cxx
+++ b/Source/cmExportBuildFileGenerator.cxx
@@ -591,8 +591,8 @@ bool cmExportBuildFileGenerator::GenerateImportCxxModuleConfigTargetInclusion(
       continue;
     }
 
-    os << "include(\"${CMAKE_CURRENT_LIST_DIR}/target-" << tgt->GetExportName()
-       << '-' << config << ".cmake\")\n";
+    os << "include(\"${CMAKE_CURRENT_LIST_DIR}/target-"
+       << tgt->GetFilesystemExportName() << '-' << config << ".cmake\")\n";
   }
 
   return true;
diff --git a/Source/cmExportInstallFileGenerator.cxx b/Source/cmExportInstallFileGenerator.cxx
index c5b9dc9bb..5c95ecd89 100644
--- a/Source/cmExportInstallFileGenerator.cxx
+++ b/Source/cmExportInstallFileGenerator.cxx
@@ -780,8 +780,8 @@ bool cmExportInstallFileGenerator::
       continue;
     }
 
-    auto prop_filename = cmStrCat("target-", tgt->GetExportName(), '-',
-                                  filename_config, ".cmake");
+    auto prop_filename = cmStrCat("target-", tgt->GetFilesystemExportName(),
+                                  '-', filename_config, ".cmake");
     prop_files.emplace_back(cmStrCat(dest, prop_filename));
     os << "include(\"${CMAKE_CURRENT_LIST_DIR}/" << prop_filename << "\")\n";
   }
diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index a40af8b49..0fe19de31 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -368,6 +368,16 @@ std::string cmGeneratorTarget::GetExportName() const
   return this->GetName();
 }
 
+std::string cmGeneratorTarget::GetFilesystemExportName() const
+{
+  auto fs_safe = this->GetExportName();
+  // First escape any `_` characters to avoid collisions.
+  cmSystemTools::ReplaceString(fs_safe, "_", "__");
+  // Escape other characters that are not generally filesystem-safe.
+  cmSystemTools::ReplaceString(fs_safe, ":", "_c");
+  return fs_safe;
+}
+
 cmValue cmGeneratorTarget::GetProperty(const std::string& prop) const
 {
   if (cmValue result =
@@ -8483,6 +8493,10 @@ bool cmGeneratorTarget::DiscoverSyntheticTargets(cmSyntheticTargetCache& cache,
         // generation.
         tgt->CopyImportedCxxModulesProperties(model);
 
+        tgt->AddLinkLibrary(*mf,
+                            cmStrCat("$<COMPILE_ONLY:", model->GetName(), '>'),
+                            GENERAL_LibraryType);
+
         // Apply usage requirements to the target.
         usage.ApplyToTarget(tgt);
 
@@ -9484,11 +9498,25 @@ bool cmGeneratorTarget::NeedDyndepForSource(std::string const& lang,
     return true;
   }
 
+  auto targetDyndep = this->NeedCxxDyndep(config);
+  if (targetDyndep == CxxModuleSupport::Unavailable) {
+    return false;
+  }
+  auto const sfProp = sf->GetProperty("CXX_SCAN_FOR_MODULES");
+  if (sfProp.IsSet()) {
+    return sfProp.IsOn();
+  }
+  return targetDyndep == CxxModuleSupport::Enabled;
+}
+
+cmGeneratorTarget::CxxModuleSupport cmGeneratorTarget::NeedCxxDyndep(
+  std::string const& config) const
+{
   bool haveRule = false;
   switch (this->HaveCxxModuleSupport(config)) {
     case Cxx20SupportLevel::MissingCxx:
     case Cxx20SupportLevel::NoCxx20:
-      return false;
+      return CxxModuleSupport::Unavailable;
     case Cxx20SupportLevel::MissingRule:
       break;
     case Cxx20SupportLevel::Supported:
@@ -9498,28 +9526,29 @@ bool cmGeneratorTarget::NeedDyndepForSource(std::string const& lang,
   bool haveGeneratorSupport =
     this->GetGlobalGenerator()->CheckCxxModuleSupport(
       cmGlobalGenerator::CxxModuleSupportQuery::Inspect);
-  auto const sfProp = sf->GetProperty("CXX_SCAN_FOR_MODULES");
-  if (sfProp.IsSet()) {
-    return sfProp.IsOn();
-  }
   auto const tgtProp = this->GetProperty("CXX_SCAN_FOR_MODULES");
   if (tgtProp.IsSet()) {
-    return tgtProp.IsOn();
+    return tgtProp.IsOn() ? CxxModuleSupport::Enabled
+                          : CxxModuleSupport::Disabled;
   }
 
-  bool policyAnswer = false;
+  CxxModuleSupport policyAnswer = CxxModuleSupport::Unavailable;
   switch (this->GetPolicyStatusCMP0155()) {
     case cmPolicies::WARN:
     case cmPolicies::OLD:
       // The OLD behavior is to not scan the source.
-      policyAnswer = false;
+      policyAnswer = CxxModuleSupport::Disabled;
       break;
     case cmPolicies::REQUIRED_ALWAYS:
     case cmPolicies::REQUIRED_IF_USED:
     case cmPolicies::NEW:
       // The NEW behavior is to scan the source if the compiler supports
       // scanning and the generator supports it.
-      policyAnswer = haveRule && haveGeneratorSupport;
+      if (haveRule && haveGeneratorSupport) {
+        policyAnswer = CxxModuleSupport::Enabled;
+      } else {
+        policyAnswer = CxxModuleSupport::Disabled;
+      }
       break;
   }
   return policyAnswer;
diff --git a/Source/cmGeneratorTarget.h b/Source/cmGeneratorTarget.h
index fd4b2ec7e..71785b6a8 100644
--- a/Source/cmGeneratorTarget.h
+++ b/Source/cmGeneratorTarget.h
@@ -99,6 +99,7 @@ public:
   cmStateEnums::TargetType GetType() const;
   const std::string& GetName() const;
   std::string GetExportName() const;
+  std::string GetFilesystemExportName() const;
 
   std::vector<std::string> GetPropertyKeys() const;
   //! Might return a nullptr if the property is not set or invalid
@@ -1340,6 +1341,13 @@ public:
                                        cmSourceFile const* sf) const;
   bool NeedDyndepForSource(std::string const& lang, std::string const& config,
                            cmSourceFile const* sf) const;
+  enum class CxxModuleSupport
+  {
+    Unavailable,
+    Enabled,
+    Disabled,
+  };
+  CxxModuleSupport NeedCxxDyndep(std::string const& config) const;
 
 private:
   void BuildFileSetInfoCache(std::string const& config) const;
diff --git a/Source/cmVisualStudio10TargetGenerator.cxx b/Source/cmVisualStudio10TargetGenerator.cxx
index d572f30b0..fbd676d78 100644
--- a/Source/cmVisualStudio10TargetGenerator.cxx
+++ b/Source/cmVisualStudio10TargetGenerator.cxx
@@ -281,6 +281,16 @@ cmVisualStudio10TargetGenerator::cmVisualStudio10TargetGenerator(
     this->Makefile->GetGeneratorConfigs(cmMakefile::ExcludeEmptyConfig);
   this->NsightTegra = gg->IsNsightTegra();
   this->Android = gg->TargetsAndroid();
+  auto scanProp = target->GetProperty("CXX_SCAN_FOR_MODULES");
+  for (auto const& config : this->Configurations) {
+    if (scanProp.IsSet()) {
+      this->ScanSourceForModuleDependencies[config] = scanProp.IsOn();
+    } else {
+      this->ScanSourceForModuleDependencies[config] =
+        target->NeedCxxDyndep(config) ==
+        cmGeneratorTarget::CxxModuleSupport::Enabled;
+    }
+  }
   for (unsigned int& version : this->NsightTegraVersion) {
     version = 0;
   }
@@ -2827,7 +2837,9 @@ void cmVisualStudio10TargetGenerator::OutputSourceSpecificFlags(
     // use them
     if (!flags.empty() || !options.empty() || !configDefines.empty() ||
         !includes.empty() || compileAsPerConfig || noWinRT ||
-        !options.empty() || needsPCHFlags || shouldScanForModules) {
+        !options.empty() || needsPCHFlags ||
+        (shouldScanForModules !=
+         this->ScanSourceForModuleDependencies[config])) {
       cmGlobalVisualStudio10Generator* gg = this->GlobalGenerator;
       cmIDEFlagTable const* flagtable = nullptr;
       const std::string& srclang = source->GetLanguage();
@@ -2855,8 +2867,10 @@ void cmVisualStudio10TargetGenerator::OutputSourceSpecificFlags(
       if (compileAsPerConfig) {
         clOptions.AddFlag("CompileAs", compileAsPerConfig);
       }
-      if (shouldScanForModules) {
-        clOptions.AddFlag("ScanSourceForModuleDependencies", "true");
+      if (shouldScanForModules !=
+          this->ScanSourceForModuleDependencies[config]) {
+        clOptions.AddFlag("ScanSourceForModuleDependencies",
+                          shouldScanForModules ? "true" : "false");
       }
       if (noWinRT) {
         clOptions.AddFlag("CompileAsWinRT", "false");
@@ -3573,8 +3587,9 @@ void cmVisualStudio10TargetGenerator::WriteClOptions(
     }
   }
 
-  // Disable C++ source scanning by default.
-  e2.Element("ScanSourceForModuleDependencies", "false");
+  e2.Element("ScanSourceForModuleDependencies",
+             this->ScanSourceForModuleDependencies[configName] ? "true"
+                                                               : "false");
 }
 
 bool cmVisualStudio10TargetGenerator::ComputeRcOptions()
diff --git a/Source/cmVisualStudio10TargetGenerator.h b/Source/cmVisualStudio10TargetGenerator.h
index 2080e9eac..1f8b2eb34 100644
--- a/Source/cmVisualStudio10TargetGenerator.h
+++ b/Source/cmVisualStudio10TargetGenerator.h
@@ -238,6 +238,7 @@ private:
   bool NsightTegra;
   bool Android;
   bool HaveCustomCommandDepfile = false;
+  std::map<std::string, bool> ScanSourceForModuleDependencies;
   unsigned int NsightTegraVersion[4];
   bool TargetCompileAsWinRT;
   std::set<std::string> IPOEnabledConfigurations;
diff --git a/Tests/RunCMake/CMakePackage/ApplePlatformGenSubdir-stdout.txt b/Tests/RunCMake/CMakePackage/ApplePlatformGenSubdir-stdout.txt
new file mode 100644
index 000000000..8821dadf3
--- /dev/null
+++ b/Tests/RunCMake/CMakePackage/ApplePlatformGenSubdir-stdout.txt
@@ -0,0 +1,3 @@
+(-- )?Hello from platform switch
+(-- )?Hello from arch switch
+(-- )?Hello from pkg_a
diff --git a/Tests/RunCMake/CMakePackage/ApplePlatformGenSubdir.cmake b/Tests/RunCMake/CMakePackage/ApplePlatformGenSubdir.cmake
new file mode 100644
index 000000000..e47266574
--- /dev/null
+++ b/Tests/RunCMake/CMakePackage/ApplePlatformGenSubdir.cmake
@@ -0,0 +1,50 @@
+set(CMAKE_INSTALL_DATADIR share)
+set(SWITCH_DIR platform/cmake)
+
+include(CMakePackageConfigHelpers)
+
+file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/pkg_a-config.cmake.in [[
+@PACKAGE_INIT@
+include("@PACKAGE_SWITCH_DIR@/platform-switch.cmake")
+include("@PACKAGE_CMAKE_INSTALL_DATADIR@/pkg_a_included.cmake")
+]])
+configure_package_config_file(
+  ${CMAKE_CURRENT_BINARY_DIR}/pkg_a-config.cmake.in
+  ${CMAKE_CURRENT_BINARY_DIR}/install/pkg_a-config.cmake
+  INSTALL_DESTINATION .
+  PATH_VARS CMAKE_INSTALL_DATADIR SWITCH_DIR
+)
+file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/install/${CMAKE_INSTALL_DATADIR}/pkg_a_included.cmake
+  [[message(STATUS "Hello from pkg_a")]]
+)
+
+# To expose re-using the same package prefix variable, we need to use a
+# different install prefix. This is really contrived and not representative of
+# what a package should do.
+generate_apple_platform_selection_file(
+  ${CMAKE_CURRENT_BINARY_DIR}/install/platform/cmake/platform-switch.cmake
+  INSTALL_PREFIX ${CMAKE_INSTALL_PREFIX}/platform
+  INSTALL_DESTINATION cmake
+  MACOS_INCLUDE_FILE cmake/switch_included.cmake  # relative to install prefix
+)
+file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/install/platform/cmake/switch_included.cmake
+[[
+message(STATUS "Hello from platform switch")
+include("${CMAKE_CURRENT_LIST_DIR}/../arch/cmake/arch-switch.cmake")
+]]
+)
+
+generate_apple_architecture_selection_file(
+  ${CMAKE_CURRENT_BINARY_DIR}/install/platform/arch/cmake/arch-switch.cmake
+  INSTALL_PREFIX ${CMAKE_INSTALL_PREFIX}/platform/arch
+  INSTALL_DESTINATION cmake
+  UNIVERSAL_ARCHITECTURES i386 x86_64 arm64 $(ARCHS_STANDARD)
+  UNIVERSAL_INCLUDE_FILE cmake/switch_included.cmake  # relative to install prefix
+)
+file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/install/platform/arch/cmake/switch_included.cmake
+  [[message(STATUS "Hello from arch switch")]]
+)
+
+find_package(pkg_a REQUIRED NO_DEFAULT_PATH
+  PATHS ${CMAKE_CURRENT_BINARY_DIR}/install
+)
diff --git a/Tests/RunCMake/CMakePackage/RunCMakeTest.cmake b/Tests/RunCMake/CMakePackage/RunCMakeTest.cmake
index 1551b55f6..3b4bef520 100644
--- a/Tests/RunCMake/CMakePackage/RunCMakeTest.cmake
+++ b/Tests/RunCMake/CMakePackage/RunCMakeTest.cmake
@@ -48,9 +48,6 @@ if(APPLE)
 endif()
 
 if(APPLE AND CMAKE_C_COMPILER_ID STREQUAL "AppleClang")
-  set(apple_install ${RunCMake_BINARY_DIR}/apple-install)
-  file(REMOVE_RECURSE "${apple_install}")
-
   if(CMake_TEST_XCODE_VERSION VERSION_GREATER_EQUAL 12)
     set(macos_archs "x86_64;arm64")
     set(tvos_sim_archs "x86_64;arm64")
@@ -78,6 +75,17 @@ if(APPLE AND CMAKE_C_COMPILER_ID STREQUAL "AppleClang")
     set(enable_visionos 1)
   endif()
 
+  string(REPLACE ";" "\\;" macos_archs_for_cmd "${macos_archs}")
+  run_cmake_with_options(ApplePlatformGenSubdir
+    "-DCMAKE_OSX_ARCHITECTURES=${macos_archs_for_cmd}"
+    ${maybe_CMAKE_BUILD_TYPE}
+  )
+  unset(macos_archs_for_cmd)
+
+  # Place all export/import steps in a single install prefix.
+  set(apple_install ${RunCMake_BINARY_DIR}/apple-install)
+  file(REMOVE_RECURSE "${apple_install}")
+
   apple_export(macos Darwin "${macos_archs}" macosx)
   apple_export(ios iOS "arm64" iphoneos)
   apple_export(tvos tvOS "arm64" appletvos)
diff --git a/Tests/RunCMake/CXXModules/NinjaDependInfoExportFilesystemSafe-check.cmake b/Tests/RunCMake/CXXModules/NinjaDependInfoExportFilesystemSafe-check.cmake
new file mode 100644
index 000000000..d08aef780
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/NinjaDependInfoExportFilesystemSafe-check.cmake
@@ -0,0 +1,39 @@
+include("${CMAKE_CURRENT_LIST_DIR}/check-json.cmake")
+
+if (RunCMake_GENERATOR_IS_MULTI_CONFIG)
+  set(have_file 0)
+  foreach (CXXModules_config IN ITEMS Release Debug RelWithDebInfo MinSizeRel)
+    if (NOT EXISTS "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/ninja-exports-public.dir/${CXXModules_config}/CXXDependInfo.json")
+      continue ()
+    endif ()
+    set(have_file 1)
+
+    set(CMAKE_BUILD_TYPE "${CXXModules_config}")
+
+    file(READ "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/ninja-exports-public.dir/${CXXModules_config}/CXXDependInfo.json" actual_contents)
+    file(READ "${CMAKE_CURRENT_LIST_DIR}/expect/NinjaDependInfoExportFilesystemSafe-public.json" expect_contents)
+    check_json("${actual_contents}" "${expect_contents}")
+
+    file(READ "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/ninja-exports-private.dir/${CXXModules_config}/CXXDependInfo.json" actual_contents)
+    file(READ "${CMAKE_CURRENT_LIST_DIR}/expect/NinjaDependInfoExportFilesystemSafe-private.json" expect_contents)
+    check_json("${actual_contents}" "${expect_contents}")
+  endforeach ()
+
+  if (NOT have_file)
+    list(APPEND RunCMake_TEST_FAILED
+      "No recognized build configurations found.")
+  endif ()
+else ()
+  set(CXXModules_config "${CXXModules_default_build_type}")
+  set(CMAKE_BUILD_TYPE "${CXXModules_default_build_type}")
+
+  file(READ "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/ninja-exports-public.dir/CXXDependInfo.json" actual_contents)
+  file(READ "${CMAKE_CURRENT_LIST_DIR}/expect/NinjaDependInfoExportFilesystemSafe-public.json" expect_contents)
+  check_json("${actual_contents}" "${expect_contents}")
+
+  file(READ "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/ninja-exports-private.dir/CXXDependInfo.json" actual_contents)
+  file(READ "${CMAKE_CURRENT_LIST_DIR}/expect/NinjaDependInfoExportFilesystemSafe-private.json" expect_contents)
+  check_json("${actual_contents}" "${expect_contents}")
+endif ()
+
+string(REPLACE ";" "\n  " RunCMake_TEST_FAILED "${RunCMake_TEST_FAILED}")
diff --git a/Tests/RunCMake/CXXModules/NinjaDependInfoExportFilesystemSafe.cmake b/Tests/RunCMake/CXXModules/NinjaDependInfoExportFilesystemSafe.cmake
new file mode 100644
index 000000000..890b5e41a
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/NinjaDependInfoExportFilesystemSafe.cmake
@@ -0,0 +1,84 @@
+# Fake out that we have dyndep; we only need to generate, not actually build
+# here.
+set(CMAKE_CXX_SCANDEP_SOURCE "")
+
+enable_language(CXX)
+
+if (NOT CMAKE_GENERATOR MATCHES "Ninja")
+  message(FATAL_ERROR
+    "This test requires a 'Ninja' generator to be used.")
+endif ()
+
+add_library(ninja-exports-public)
+target_sources(ninja-exports-public
+  PRIVATE
+    sources/module-impl.cxx
+    sources/module-internal-part-impl.cxx
+    sources/module-part-impl.cxx
+    sources/module-use.cxx
+  PUBLIC
+    FILE_SET modules TYPE CXX_MODULES
+    BASE_DIRS
+      "${CMAKE_CURRENT_SOURCE_DIR}/sources"
+    FILES
+      sources/module.cxx
+      sources/module-part.cxx
+    FILE_SET internal_partitions TYPE CXX_MODULES FILES
+      sources/module-internal-part.cxx)
+target_compile_features(ninja-exports-public
+  PRIVATE
+    cxx_std_20)
+set_property(TARGET ninja-exports-public
+  PROPERTY EXPORT_NAME "with::public_")
+
+install(TARGETS ninja-exports-public
+  EXPORT exp
+  FILE_SET modules
+    DESTINATION "lib/cxx"
+    COMPONENT "modules"
+  FILE_SET internal_partitions
+    DESTINATION "lib/cxx/internals"
+    COMPONENT "modules-internal")
+
+add_library(ninja-exports-private)
+target_sources(ninja-exports-private
+  PRIVATE
+    sources/module-impl.cxx
+    sources/module-internal-part-impl.cxx
+    sources/module-part-impl.cxx
+    sources/module-use.cxx
+  PRIVATE
+    FILE_SET modules TYPE CXX_MODULES
+    BASE_DIRS
+      "${CMAKE_CURRENT_SOURCE_DIR}/sources"
+    FILES
+      sources/module.cxx
+      sources/module-part.cxx
+    FILE_SET internal_partitions TYPE CXX_MODULES FILES
+      sources/module-internal-part.cxx)
+target_compile_features(ninja-exports-private
+  PRIVATE
+    cxx_std_20)
+set_property(TARGET ninja-exports-private
+  PROPERTY EXPORT_NAME "with::private_")
+
+install(TARGETS ninja-exports-private
+  EXPORT exp)
+
+# Test multiple build exports.
+export(EXPORT exp
+  FILE "${CMAKE_BINARY_DIR}/lib/cmake/export1/export1-targets.cmake"
+  NAMESPACE export1::
+  CXX_MODULES_DIRECTORY "cxx-modules")
+export(EXPORT exp
+  FILE "${CMAKE_BINARY_DIR}/lib/cmake/export2/export2-targets.cmake"
+  CXX_MODULES_DIRECTORY "cxx-modules")
+
+# Test multiple install exports.
+install(EXPORT exp
+  DESTINATION "lib/cmake/export1"
+  NAMESPACE export1::
+  CXX_MODULES_DIRECTORY "cxx-modules")
+install(EXPORT exp
+  DESTINATION "lib/cmake/export2"
+  CXX_MODULES_DIRECTORY "cxx-modules")
diff --git a/Tests/RunCMake/CXXModules/RunCMakeTest.cmake b/Tests/RunCMake/CXXModules/RunCMakeTest.cmake
index 14829a164..23c32c008 100644
--- a/Tests/RunCMake/CXXModules/RunCMakeTest.cmake
+++ b/Tests/RunCMake/CXXModules/RunCMakeTest.cmake
@@ -95,6 +95,7 @@ run_cmake(ExportInstallCxxModules)
 if (RunCMake_GENERATOR MATCHES "Ninja")
   run_cmake(NinjaDependInfoFileSet)
   run_cmake(NinjaDependInfoExport)
+  run_cmake(NinjaDependInfoExportFilesystemSafe)
   run_cmake(NinjaDependInfoBMIInstall)
   run_cmake(NinjaForceResponseFile) # issue#25367
 elseif (RunCMake_GENERATOR MATCHES "Visual Studio")
@@ -264,9 +265,11 @@ if ("export_bmi" IN_LIST CMake_TEST_MODULE_COMPILATION)
   run_cxx_module_test(export-include-directories-old-cmake-build)
   run_cxx_module_test(export-usage-build)
   run_cxx_module_test(export-bmi-and-interface-build)
+  run_cxx_module_test(export-command-sepdir-build)
   run_cxx_module_test(export-transitive-targets-build)
   run_cxx_module_test(export-transitive-modules1-build)
   run_cxx_module_test(export-transitive-modules-build export-transitive-modules-build "-DCMAKE_PREFIX_PATH=${RunCMake_BINARY_DIR}/examples/export-transitive-modules1-build-build" )
+  run_cxx_module_test(export-with-headers-build)
 
   if ("collation" IN_LIST CMake_TEST_MODULE_COMPILATION AND
       "bmionly" IN_LIST CMake_TEST_MODULE_COMPILATION)
@@ -282,11 +285,17 @@ if ("export_bmi" IN_LIST CMake_TEST_MODULE_COMPILATION)
     set(test_suffix export-bmi-and-interface-build)
     run_cxx_module_test(import-modules "import-modules-${test_suffix}" "-DCMAKE_PREFIX_PATH=${RunCMake_BINARY_DIR}/examples/${test_suffix}-build" -DWITH_BMIS=1)
 
+    set(test_suffix export-command-sepdir-build)
+    run_cxx_module_test(import-modules "import-modules-${test_suffix}" "-DCMAKE_PREFIX_PATH=${RunCMake_BINARY_DIR}/examples/${test_suffix}-build" -DEXPORT_COMMAND_SEPDIR=1)
+
     set(test_suffix export-transitive-targets-build)
     run_cxx_module_test(import-modules "import-modules-${test_suffix}" "-DCMAKE_PREFIX_PATH=${RunCMake_BINARY_DIR}/examples/${test_suffix}-build" -DTRANSITIVE_TARGETS=1)
 
     set(test_suffix export-transitive-modules-build)
     run_cxx_module_test(import-modules "import-modules-${test_suffix}" "-DCMAKE_PREFIX_PATH=${RunCMake_BINARY_DIR}/examples/${test_suffix}-build" -DTRANSITIVE_MODULES=1)
+
+    set(test_suffix export-with-headers-build)
+    run_cxx_module_test(import-modules "import-modules-${test_suffix}" "-DCMAKE_PREFIX_PATH=${RunCMake_BINARY_DIR}/examples/${test_suffix}-build" -DWITH_HEADERS=1)
   endif ()
 endif ()
 
@@ -305,9 +314,11 @@ if ("install_bmi" IN_LIST CMake_TEST_MODULE_COMPILATION)
     run_cxx_module_test(export-include-directories-old-cmake-install)
     run_cxx_module_test(export-usage-install)
     run_cxx_module_test(export-bmi-and-interface-install)
+    run_cxx_module_test(export-command-sepdir-install)
     run_cxx_module_test(export-transitive-targets-install)
     run_cxx_module_test(export-transitive-modules1-install)
     run_cxx_module_test(export-transitive-modules-install export-transitive-modules-install "-DCMAKE_PREFIX_PATH=${RunCMake_BINARY_DIR}/examples/export-transitive-modules1-install-install" )
+    run_cxx_module_test(export-with-headers-install)
 
     if ("collation" IN_LIST CMake_TEST_MODULE_COMPILATION AND
         "bmionly" IN_LIST CMake_TEST_MODULE_COMPILATION)
@@ -324,11 +335,17 @@ if ("install_bmi" IN_LIST CMake_TEST_MODULE_COMPILATION)
       set(test_suffix export-bmi-and-interface-install)
       run_cxx_module_test(import-modules "import-modules-${test_suffix}" "-DCMAKE_PREFIX_PATH=${RunCMake_BINARY_DIR}/examples/${test_suffix}-install" -DWITH_BMIS=1)
 
+      set(test_suffix export-command-sepdir-install)
+      run_cxx_module_test(import-modules "import-modules-${test_suffix}" "-DCMAKE_PREFIX_PATH=${RunCMake_BINARY_DIR}/examples/${test_suffix}-install" -DEXPORT_COMMAND_SEPDIR=1)
+
       set(test_suffix export-transitive-targets-install)
       run_cxx_module_test(import-modules "import-modules-${test_suffix}" "-DCMAKE_PREFIX_PATH=${RunCMake_BINARY_DIR}/examples/${test_suffix}-install" -DTRANSITIVE_TARGETS=1)
 
       set(test_suffix export-transitive-modules-install)
       run_cxx_module_test(import-modules "import-modules-${test_suffix}" "-DCMAKE_PREFIX_PATH=${RunCMake_BINARY_DIR}/examples/${test_suffix}-install" -DTRANSITIVE_MODULES=1)
+
+      set(test_suffix export-with-headers-install)
+      run_cxx_module_test(import-modules "import-modules-${test_suffix}" "-DCMAKE_PREFIX_PATH=${RunCMake_BINARY_DIR}/examples/${test_suffix}-install" -DWITH_HEADERS=1)
       set(RunCMake_CXXModules_INSTALL 1)
     endif ()
   endif ()
diff --git a/Tests/RunCMake/CXXModules/examples/export-command-sepdir-build/CMakeLists.txt b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-build/CMakeLists.txt
new file mode 100644
index 000000000..4f3fcf8a3
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-build/CMakeLists.txt
@@ -0,0 +1,37 @@
+cmake_minimum_required(VERSION 3.24...3.28)
+project(cxx_modules_export_sepdir CXX)
+
+include("${CMAKE_SOURCE_DIR}/../cxx-modules-rules.cmake")
+
+add_subdirectory(subdir)
+
+install(TARGETS export_sepdir
+  EXPORT CXXModules
+  FILE_SET modules DESTINATION "lib/cxx/miu")
+export(EXPORT CXXModules
+  NAMESPACE CXXModules::
+  FILE "${CMAKE_CURRENT_BINARY_DIR}/export_sepdir-targets.cmake")
+file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/export_sepdir-config.cmake"
+  "include(\"\${CMAKE_CURRENT_LIST_DIR}/export_sepdir-targets.cmake\")
+set(\${CMAKE_FIND_PACKAGE_NAME}_FOUND 1)
+")
+
+set(generator
+  -G "${CMAKE_GENERATOR}")
+if (CMAKE_GENERATOR_TOOLSET)
+  list(APPEND generator
+    -T "${CMAKE_GENERATOR_TOOLSET}")
+endif ()
+if (CMAKE_GENERATOR_PLATFORM)
+  list(APPEND generator
+    -A "${CMAKE_GENERATOR_PLATFORM}")
+endif ()
+
+add_test(NAME export_sepdir_build
+  COMMAND
+    "${CMAKE_COMMAND}"
+    "-Dexpected_dir=${CMAKE_CURRENT_SOURCE_DIR}"
+    "-Dexport_sepdir_DIR=${CMAKE_CURRENT_BINARY_DIR}"
+    ${generator}
+    -S "${CMAKE_CURRENT_SOURCE_DIR}/test"
+    -B "${CMAKE_CURRENT_BINARY_DIR}/test")
diff --git a/Tests/RunCMake/CXXModules/examples/export-command-sepdir-build/subdir/CMakeLists.txt b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-build/subdir/CMakeLists.txt
new file mode 100644
index 000000000..cd571f694
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-build/subdir/CMakeLists.txt
@@ -0,0 +1,9 @@
+add_library(export_sepdir STATIC)
+target_sources(export_sepdir
+  PUBLIC
+    FILE_SET modules TYPE CXX_MODULES
+      BASE_DIRS
+        "${CMAKE_CURRENT_SOURCE_DIR}"
+      FILES
+        importable.cxx)
+target_compile_features(export_sepdir PUBLIC cxx_std_20)
diff --git a/Tests/RunCMake/CXXModules/examples/export-command-sepdir-build/subdir/importable.cxx b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-build/subdir/importable.cxx
new file mode 100644
index 000000000..607680a07
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-build/subdir/importable.cxx
@@ -0,0 +1,6 @@
+export module importable;
+
+export int from_import()
+{
+  return 0;
+}
diff --git a/Tests/RunCMake/CXXModules/examples/export-command-sepdir-build/test/CMakeLists.txt b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-build/test/CMakeLists.txt
new file mode 100644
index 000000000..d39327158
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-build/test/CMakeLists.txt
@@ -0,0 +1,16 @@
+cmake_minimum_required(VERSION 3.24...3.28)
+project(cxx_modules_library NONE)
+
+find_package(export_sepdir REQUIRED)
+
+if (NOT TARGET CXXModules::export_sepdir)
+  message(FATAL_ERROR
+    "Missing imported target")
+endif ()
+
+get_property(modules TARGET CXXModules::export_sepdir
+  PROPERTY "IMPORTED_CXX_MODULES_NOCONFIG")
+if (modules STREQUAL "")
+  message(SEND_ERROR
+    "Expected non-empty property value for IMPORTED_CXX_MODULES_NOCONFIG")
+endif ()
diff --git a/Tests/RunCMake/CXXModules/examples/export-command-sepdir-install/CMakeLists.txt b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-install/CMakeLists.txt
new file mode 100644
index 000000000..de21a2e61
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-install/CMakeLists.txt
@@ -0,0 +1,40 @@
+cmake_minimum_required(VERSION 3.24...3.28)
+project(cxx_modules_export_sepdir CXX)
+
+include("${CMAKE_SOURCE_DIR}/../cxx-modules-rules.cmake")
+
+add_subdirectory(subdir)
+
+install(TARGETS export_sepdir
+  EXPORT CXXModules
+  FILE_SET modules DESTINATION "lib/cxx/miu")
+install(EXPORT CXXModules
+  NAMESPACE CXXModules::
+  DESTINATION "lib/cmake/export_sepdir"
+  FILE "export_sepdir-targets.cmake")
+file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/export_sepdir-config.cmake"
+  "include(\"\${CMAKE_CURRENT_LIST_DIR}/export_sepdir-targets.cmake\")
+set(\${CMAKE_FIND_PACKAGE_NAME}_FOUND 1)
+")
+install(FILES "${CMAKE_CURRENT_BINARY_DIR}/export_sepdir-config.cmake"
+  DESTINATION "lib/cmake/export_sepdir")
+
+set(generator
+  -G "${CMAKE_GENERATOR}")
+if (CMAKE_GENERATOR_TOOLSET)
+  list(APPEND generator
+    -T "${CMAKE_GENERATOR_TOOLSET}")
+endif ()
+if (CMAKE_GENERATOR_PLATFORM)
+  list(APPEND generator
+    -A "${CMAKE_GENERATOR_PLATFORM}")
+endif ()
+
+add_test(NAME export_sepdir_build
+  COMMAND
+    "${CMAKE_COMMAND}"
+    "-Dexpected_dir=${CMAKE_INSTALL_PREFIX}/lib/cxx/miu"
+    "-Dexport_sepdir_DIR=${CMAKE_INSTALL_PREFIX}/lib/cmake/export_sepdir"
+    ${generator}
+    -S "${CMAKE_CURRENT_SOURCE_DIR}/test"
+    -B "${CMAKE_CURRENT_BINARY_DIR}/test")
diff --git a/Tests/RunCMake/CXXModules/examples/export-command-sepdir-install/subdir/CMakeLists.txt b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-install/subdir/CMakeLists.txt
new file mode 100644
index 000000000..cd571f694
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-install/subdir/CMakeLists.txt
@@ -0,0 +1,9 @@
+add_library(export_sepdir STATIC)
+target_sources(export_sepdir
+  PUBLIC
+    FILE_SET modules TYPE CXX_MODULES
+      BASE_DIRS
+        "${CMAKE_CURRENT_SOURCE_DIR}"
+      FILES
+        importable.cxx)
+target_compile_features(export_sepdir PUBLIC cxx_std_20)
diff --git a/Tests/RunCMake/CXXModules/examples/export-command-sepdir-install/subdir/importable.cxx b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-install/subdir/importable.cxx
new file mode 100644
index 000000000..607680a07
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-install/subdir/importable.cxx
@@ -0,0 +1,6 @@
+export module importable;
+
+export int from_import()
+{
+  return 0;
+}
diff --git a/Tests/RunCMake/CXXModules/examples/export-command-sepdir-install/test/CMakeLists.txt b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-install/test/CMakeLists.txt
new file mode 100644
index 000000000..d39327158
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-command-sepdir-install/test/CMakeLists.txt
@@ -0,0 +1,16 @@
+cmake_minimum_required(VERSION 3.24...3.28)
+project(cxx_modules_library NONE)
+
+find_package(export_sepdir REQUIRED)
+
+if (NOT TARGET CXXModules::export_sepdir)
+  message(FATAL_ERROR
+    "Missing imported target")
+endif ()
+
+get_property(modules TARGET CXXModules::export_sepdir
+  PROPERTY "IMPORTED_CXX_MODULES_NOCONFIG")
+if (modules STREQUAL "")
+  message(SEND_ERROR
+    "Expected non-empty property value for IMPORTED_CXX_MODULES_NOCONFIG")
+endif ()
diff --git a/Tests/RunCMake/CXXModules/examples/export-with-headers-build/CMakeLists.txt b/Tests/RunCMake/CXXModules/examples/export-with-headers-build/CMakeLists.txt
new file mode 100644
index 000000000..e329189e3
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-with-headers-build/CMakeLists.txt
@@ -0,0 +1,49 @@
+cmake_minimum_required(VERSION 3.28)
+project(export_with_headers CXX)
+
+include("${CMAKE_SOURCE_DIR}/../cxx-modules-rules.cmake")
+
+add_library(export_with_headers)
+target_sources(export_with_headers
+  PUBLIC
+    FILE_SET headers TYPE HEADERS
+    BASE_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/include"
+    FILES
+      "${CMAKE_CURRENT_SOURCE_DIR}/include/subdir/header.h"
+  PUBLIC
+    FILE_SET modules TYPE CXX_MODULES
+    FILES
+      importable.cxx)
+target_compile_features(export_with_headers PUBLIC cxx_std_20)
+
+install(TARGETS export_with_headers
+  EXPORT CXXModules
+  FILE_SET headers
+  FILE_SET modules DESTINATION ${CMAKE_INSTALL_LIBDIR}/miu)
+export(EXPORT CXXModules
+  NAMESPACE CXXModules::
+  FILE "${CMAKE_CURRENT_BINARY_DIR}/export_with_headers-targets.cmake"
+  CXX_MODULES_DIRECTORY "export_with_headers-cxx-modules")
+file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/export_with_headers-config.cmake"
+  "include(\"\${CMAKE_CURRENT_LIST_DIR}/export_with_headers-targets.cmake\")
+set(\${CMAKE_FIND_PACKAGE_NAME}_FOUND 1)
+")
+
+set(generator
+  -G "${CMAKE_GENERATOR}")
+if (CMAKE_GENERATOR_TOOLSET)
+  list(APPEND generator
+    -T "${CMAKE_GENERATOR_TOOLSET}")
+endif ()
+if (CMAKE_GENERATOR_PLATFORM)
+  list(APPEND generator
+    -A "${CMAKE_GENERATOR_PLATFORM}")
+endif ()
+
+add_test(NAME export_with_headers_build
+  COMMAND
+    "${CMAKE_COMMAND}"
+    "-Dexport_with_headers_DIR=${CMAKE_CURRENT_BINARY_DIR}"
+    ${generator}
+    -S "${CMAKE_CURRENT_SOURCE_DIR}/test"
+    -B "${CMAKE_CURRENT_BINARY_DIR}/test")
diff --git a/Tests/RunCMake/CXXModules/examples/export-with-headers-build/importable.cxx b/Tests/RunCMake/CXXModules/examples/export-with-headers-build/importable.cxx
new file mode 100644
index 000000000..83d5b5070
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-with-headers-build/importable.cxx
@@ -0,0 +1,14 @@
+module;
+
+#include <subdir/header.h>
+
+#ifndef from_subdir_header_h
+#  error "Define from header found"
+#endif
+
+export module importable;
+
+export int from_import()
+{
+  return 0;
+}
diff --git a/Tests/RunCMake/CXXModules/examples/export-with-headers-build/include/subdir/header.h b/Tests/RunCMake/CXXModules/examples/export-with-headers-build/include/subdir/header.h
new file mode 100644
index 000000000..81e821502
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-with-headers-build/include/subdir/header.h
@@ -0,0 +1,3 @@
+#pragma once
+
+#define from_subdir_header_h 1
diff --git a/Tests/RunCMake/CXXModules/examples/export-with-headers-build/test/CMakeLists.txt b/Tests/RunCMake/CXXModules/examples/export-with-headers-build/test/CMakeLists.txt
new file mode 100644
index 000000000..11b0daeb0
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-with-headers-build/test/CMakeLists.txt
@@ -0,0 +1,19 @@
+cmake_minimum_required(VERSION 3.28)
+project(cxx_modules_library NONE)
+
+find_package(export_with_headers REQUIRED)
+
+if (NOT TARGET CXXModules::export_with_headers)
+  message(FATAL_ERROR
+    "Missing imported target")
+endif ()
+
+get_property(iface_includes TARGET CXXModules::export_with_headers
+  PROPERTY INTERFACE_INCLUDE_DIRECTORIES)
+set(include_dir "${CMAKE_CURRENT_SOURCE_DIR}")
+cmake_path(GET include_dir PARENT_PATH include_dir)
+string(APPEND include_dir "/include")
+if (NOT iface_includes STREQUAL "${include_dir};$<BUILD_INTERFACE:${include_dir}>")
+  message(FATAL_ERROR
+    "Incorrect include interface for CXXModules::export_with_headers:\n  ${iface_includes}")
+endif ()
diff --git a/Tests/RunCMake/CXXModules/examples/export-with-headers-install/CMakeLists.txt b/Tests/RunCMake/CXXModules/examples/export-with-headers-install/CMakeLists.txt
new file mode 100644
index 000000000..f6aefaf8e
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-with-headers-install/CMakeLists.txt
@@ -0,0 +1,51 @@
+cmake_minimum_required(VERSION 3.28)
+project(export_with_headers CXX)
+
+include("${CMAKE_SOURCE_DIR}/../cxx-modules-rules.cmake")
+
+add_library(export_with_headers)
+target_sources(export_with_headers
+  PUBLIC
+    FILE_SET headers TYPE HEADERS
+    BASE_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/include"
+    FILES
+      "${CMAKE_CURRENT_SOURCE_DIR}/include/subdir/header.h"
+  PUBLIC
+    FILE_SET modules TYPE CXX_MODULES
+    FILES
+      importable.cxx)
+target_compile_features(export_with_headers PUBLIC cxx_std_20)
+
+install(TARGETS export_with_headers
+  EXPORT CXXModules
+  FILE_SET headers
+  FILE_SET modules DESTINATION lib/miu)
+install(EXPORT CXXModules
+  NAMESPACE CXXModules::
+  DESTINATION "lib/cmake/export_with_headers"
+  FILE "export_with_headers-targets.cmake")
+file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/export_with_headers-config.cmake"
+  "include(\"\${CMAKE_CURRENT_LIST_DIR}/export_with_headers-targets.cmake\")
+set(\${CMAKE_FIND_PACKAGE_NAME}_FOUND 1)
+")
+install(FILES "${CMAKE_CURRENT_BINARY_DIR}/export_with_headers-config.cmake"
+  DESTINATION "lib/cmake/export_with_headers")
+
+set(generator
+  -G "${CMAKE_GENERATOR}")
+if (CMAKE_GENERATOR_TOOLSET)
+  list(APPEND generator
+    -T "${CMAKE_GENERATOR_TOOLSET}")
+endif ()
+if (CMAKE_GENERATOR_PLATFORM)
+  list(APPEND generator
+    -A "${CMAKE_GENERATOR_PLATFORM}")
+endif ()
+
+add_test(NAME export_with_headers_build
+  COMMAND
+    "${CMAKE_COMMAND}"
+    "-Dexport_with_headers_DIR=${CMAKE_INSTALL_PREFIX}/lib/cmake/export_with_headers"
+    ${generator}
+    -S "${CMAKE_CURRENT_SOURCE_DIR}/test"
+    -B "${CMAKE_CURRENT_BINARY_DIR}/test")
diff --git a/Tests/RunCMake/CXXModules/examples/export-with-headers-install/importable.cxx b/Tests/RunCMake/CXXModules/examples/export-with-headers-install/importable.cxx
new file mode 100644
index 000000000..83d5b5070
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-with-headers-install/importable.cxx
@@ -0,0 +1,14 @@
+module;
+
+#include <subdir/header.h>
+
+#ifndef from_subdir_header_h
+#  error "Define from header found"
+#endif
+
+export module importable;
+
+export int from_import()
+{
+  return 0;
+}
diff --git a/Tests/RunCMake/CXXModules/examples/export-with-headers-install/include/subdir/header.h b/Tests/RunCMake/CXXModules/examples/export-with-headers-install/include/subdir/header.h
new file mode 100644
index 000000000..81e821502
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-with-headers-install/include/subdir/header.h
@@ -0,0 +1,3 @@
+#pragma once
+
+#define from_subdir_header_h 1
diff --git a/Tests/RunCMake/CXXModules/examples/export-with-headers-install/test/CMakeLists.txt b/Tests/RunCMake/CXXModules/examples/export-with-headers-install/test/CMakeLists.txt
new file mode 100644
index 000000000..40d66cbcf
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/examples/export-with-headers-install/test/CMakeLists.txt
@@ -0,0 +1,21 @@
+cmake_minimum_required(VERSION 3.28)
+project(cxx_modules_library NONE)
+
+find_package(export_with_headers REQUIRED)
+
+if (NOT TARGET CXXModules::export_with_headers)
+  message(FATAL_ERROR
+    "Missing imported target")
+endif ()
+
+get_property(iface_includes TARGET CXXModules::export_with_headers
+  PROPERTY INTERFACE_INCLUDE_DIRECTORIES)
+set(include_dir "${export_with_headers_DIR}")
+cmake_path(GET include_dir PARENT_PATH include_dir)
+cmake_path(GET include_dir PARENT_PATH include_dir)
+cmake_path(GET include_dir PARENT_PATH include_dir)
+string(APPEND include_dir "/include")
+if (NOT iface_includes STREQUAL "$<BUILD_INTERFACE:${include_dir}>")
+  message(FATAL_ERROR
+    "Incorrect include interface for CXXModules::export_with_headers:\n  ${iface_includes}")
+endif ()
diff --git a/Tests/RunCMake/CXXModules/examples/import-modules/CMakeLists.txt b/Tests/RunCMake/CXXModules/examples/import-modules/CMakeLists.txt
index c2bbb2e9b..6796660ba 100644
--- a/Tests/RunCMake/CXXModules/examples/import-modules/CMakeLists.txt
+++ b/Tests/RunCMake/CXXModules/examples/import-modules/CMakeLists.txt
@@ -7,6 +7,8 @@ if (NO_PROPERTIES)
   set(package_name "export_interfaces_no_properties")
 elseif (WITH_BMIS)
   set(package_name "export_bmi_and_interfaces")
+elseif (EXPORT_COMMAND_SEPDIR)
+  set(package_name "export_sepdir")
 elseif (INCLUDE_PROPERTIES)
   set(package_name "export_include_directories")
 elseif (FROM_NINJA)
@@ -15,6 +17,8 @@ elseif (TRANSITIVE_TARGETS)
   set(package_name "export_transitive_targets")
 elseif (TRANSITIVE_MODULES)
   set(package_name "export_transitive_modules")
+elseif (WITH_HEADERS)
+  set(package_name "export_with_headers")
 else ()
   set(package_name "export_interfaces")
 endif ()
diff --git a/Tests/RunCMake/CXXModules/expect/NinjaDependInfoExport-private.json b/Tests/RunCMake/CXXModules/expect/NinjaDependInfoExport-private.json
index 61f8f6476..71b2b66e8 100644
--- a/Tests/RunCMake/CXXModules/expect/NinjaDependInfoExport-private.json
+++ b/Tests/RunCMake/CXXModules/expect/NinjaDependInfoExport-private.json
@@ -43,6 +43,7 @@
       "destination" : "lib/cmake/export1",
       "export-name" : "with-private",
       "export-prefix" : "<BINARY_DIR>/CMakeFiles/Export/d2e2673818fd2bd8c45c0e3ed0e38fcd",
+      "filesystem-export-name" : "with-private",
       "install" : true,
       "namespace" : "export1::"
     },
@@ -51,6 +52,7 @@
       "destination" : "lib/cmake/export2",
       "export-name" : "with-private",
       "export-prefix" : "<BINARY_DIR>/CMakeFiles/Export/28cd47cb4c96ad5cadaa3fb1b0201ae8",
+      "filesystem-export-name" : "with-private",
       "install" : true,
       "namespace" : ""
     },
@@ -59,6 +61,7 @@
       "destination" : "<BINARY_DIR>/lib/cmake/export1",
       "export-name" : "with-private",
       "export-prefix" : "<BINARY_DIR>/lib/cmake/export1",
+      "filesystem-export-name" : "with-private",
       "install" : false,
       "namespace" : "export1::"
     },
@@ -67,6 +70,7 @@
       "destination" : "<BINARY_DIR>/lib/cmake/export2",
       "export-name" : "with-private",
       "export-prefix" : "<BINARY_DIR>/lib/cmake/export2",
+      "filesystem-export-name" : "with-private",
       "install" : false,
       "namespace" : ""
     }
diff --git a/Tests/RunCMake/CXXModules/expect/NinjaDependInfoExport-public.json b/Tests/RunCMake/CXXModules/expect/NinjaDependInfoExport-public.json
index d0263b0b9..a9cde991a 100644
--- a/Tests/RunCMake/CXXModules/expect/NinjaDependInfoExport-public.json
+++ b/Tests/RunCMake/CXXModules/expect/NinjaDependInfoExport-public.json
@@ -43,6 +43,7 @@
       "destination" : "lib/cmake/export1",
       "export-name" : "with-public",
       "export-prefix" : "<BINARY_DIR>/CMakeFiles/Export/d2e2673818fd2bd8c45c0e3ed0e38fcd",
+      "filesystem-export-name" : "with-public",
       "install" : true,
       "namespace" : "export1::"
     },
@@ -51,6 +52,7 @@
       "destination" : "lib/cmake/export2",
       "export-name" : "with-public",
       "export-prefix" : "<BINARY_DIR>/CMakeFiles/Export/28cd47cb4c96ad5cadaa3fb1b0201ae8",
+      "filesystem-export-name" : "with-public",
       "install" : true,
       "namespace" : ""
     },
@@ -59,6 +61,7 @@
       "destination" : "<BINARY_DIR>/lib/cmake/export1",
       "export-name" : "with-public",
       "export-prefix" : "<BINARY_DIR>/lib/cmake/export1",
+      "filesystem-export-name" : "with-public",
       "install" : false,
       "namespace" : "export1::"
     },
@@ -67,6 +70,7 @@
       "destination" : "<BINARY_DIR>/lib/cmake/export2",
       "export-name" : "with-public",
       "export-prefix" : "<BINARY_DIR>/lib/cmake/export2",
+      "filesystem-export-name" : "with-public",
       "install" : false,
       "namespace" : ""
     }
diff --git a/Tests/RunCMake/CXXModules/expect/NinjaDependInfoExportFilesystemSafe-private.json b/Tests/RunCMake/CXXModules/expect/NinjaDependInfoExportFilesystemSafe-private.json
new file mode 100644
index 000000000..7905c535f
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/expect/NinjaDependInfoExportFilesystemSafe-private.json
@@ -0,0 +1,83 @@
+{
+  "bmi-installation": null,
+  "compiler-id": "<IGNORE>",
+  "compiler-frontend-variant": "<IGNORE>",
+  "compiler-simulate-id": "<IGNORE>",
+  "config": "<CONFIG>",
+  "cxx-modules": {
+    "CMakeFiles/ninja-exports-private.dir<CONFIG_DIR>/sources/module-internal-part.cxx<OBJEXT>": {
+      "bmi-only": false,
+      "destination": null,
+      "name": "internal_partitions",
+      "relative-directory": "sources",
+      "source": "<SOURCE_DIR>/sources/module-internal-part.cxx",
+      "type": "CXX_MODULES",
+      "visibility": "PRIVATE"
+    },
+    "CMakeFiles/ninja-exports-private.dir<CONFIG_DIR>/sources/module-part.cxx<OBJEXT>": {
+      "bmi-only": false,
+      "destination": null,
+      "name": "modules",
+      "relative-directory": "",
+      "source": "<SOURCE_DIR>/sources/module-part.cxx",
+      "type": "CXX_MODULES",
+      "visibility": "PRIVATE"
+    },
+    "CMakeFiles/ninja-exports-private.dir<CONFIG_DIR>/sources/module.cxx<OBJEXT>": {
+      "bmi-only": false,
+      "destination": null,
+      "name": "modules",
+      "relative-directory": "",
+      "source": "<SOURCE_DIR>/sources/module.cxx",
+      "type": "CXX_MODULES",
+      "visibility": "PRIVATE"
+    }
+  },
+  "dir-cur-bld": "<BINARY_DIR>",
+  "dir-cur-src": "<SOURCE_DIR>",
+  "dir-top-bld": "<BINARY_DIR>",
+  "dir-top-src": "<SOURCE_DIR>",
+  "exports": [
+    {
+      "cxx-module-info-dir" : "cxx-modules",
+      "destination" : "lib/cmake/export1",
+      "export-name" : "with::private_",
+      "export-prefix" : "<BINARY_DIR>/CMakeFiles/Export/d2e2673818fd2bd8c45c0e3ed0e38fcd",
+      "filesystem-export-name" : "with_c_cprivate__",
+      "install" : true,
+      "namespace" : "export1::"
+    },
+    {
+      "cxx-module-info-dir" : "cxx-modules",
+      "destination" : "lib/cmake/export2",
+      "export-name" : "with::private_",
+      "filesystem-export-name" : "with_c_cprivate__",
+      "export-prefix" : "<BINARY_DIR>/CMakeFiles/Export/28cd47cb4c96ad5cadaa3fb1b0201ae8",
+      "install" : true,
+      "namespace" : ""
+    },
+    {
+      "cxx-module-info-dir" : "cxx-modules",
+      "destination" : "<BINARY_DIR>/lib/cmake/export1",
+      "export-name" : "with::private_",
+      "export-prefix" : "<BINARY_DIR>/lib/cmake/export1",
+      "filesystem-export-name" : "with_c_cprivate__",
+      "install" : false,
+      "namespace" : "export1::"
+    },
+    {
+      "cxx-module-info-dir" : "cxx-modules",
+      "destination" : "<BINARY_DIR>/lib/cmake/export2",
+      "export-name" : "with::private_",
+      "export-prefix" : "<BINARY_DIR>/lib/cmake/export2",
+      "filesystem-export-name" : "with_c_cprivate__",
+      "install" : false,
+      "namespace" : ""
+    }
+  ],
+  "include-dirs": [],
+  "language": "CXX",
+  "forward-modules-from-target-dirs": [],
+  "linked-target-dirs": [],
+  "module-dir": "<BINARY_DIR>/CMakeFiles/ninja-exports-private.dir<CONFIG_DIR>"
+}
diff --git a/Tests/RunCMake/CXXModules/expect/NinjaDependInfoExportFilesystemSafe-public.json b/Tests/RunCMake/CXXModules/expect/NinjaDependInfoExportFilesystemSafe-public.json
new file mode 100644
index 000000000..1734590a9
--- /dev/null
+++ b/Tests/RunCMake/CXXModules/expect/NinjaDependInfoExportFilesystemSafe-public.json
@@ -0,0 +1,83 @@
+{
+  "bmi-installation": null,
+  "compiler-id": "<IGNORE>",
+  "compiler-frontend-variant": "<IGNORE>",
+  "compiler-simulate-id": "<IGNORE>",
+  "config": "<CONFIG>",
+  "cxx-modules": {
+    "CMakeFiles/ninja-exports-public.dir<CONFIG_DIR>/sources/module-internal-part.cxx<OBJEXT>": {
+      "bmi-only": false,
+      "destination": "lib/cxx/internals",
+      "name": "internal_partitions",
+      "relative-directory": "sources",
+      "source": "<SOURCE_DIR>/sources/module-internal-part.cxx",
+      "type": "CXX_MODULES",
+      "visibility": "PUBLIC"
+    },
+    "CMakeFiles/ninja-exports-public.dir<CONFIG_DIR>/sources/module-part.cxx<OBJEXT>": {
+      "bmi-only": false,
+      "destination": "lib/cxx",
+      "name": "modules",
+      "relative-directory": "",
+      "source": "<SOURCE_DIR>/sources/module-part.cxx",
+      "type": "CXX_MODULES",
+      "visibility": "PUBLIC"
+    },
+    "CMakeFiles/ninja-exports-public.dir<CONFIG_DIR>/sources/module.cxx<OBJEXT>": {
+      "bmi-only": false,
+      "destination": "lib/cxx",
+      "name": "modules",
+      "relative-directory": "",
+      "source": "<SOURCE_DIR>/sources/module.cxx",
+      "type": "CXX_MODULES",
+      "visibility": "PUBLIC"
+    }
+  },
+  "dir-cur-bld": "<BINARY_DIR>",
+  "dir-cur-src": "<SOURCE_DIR>",
+  "dir-top-bld": "<BINARY_DIR>",
+  "dir-top-src": "<SOURCE_DIR>",
+  "exports": [
+    {
+      "cxx-module-info-dir" : "cxx-modules",
+      "destination" : "lib/cmake/export1",
+      "export-name" : "with::public_",
+      "export-prefix" : "<BINARY_DIR>/CMakeFiles/Export/d2e2673818fd2bd8c45c0e3ed0e38fcd",
+      "filesystem-export-name" : "with_c_cpublic__",
+      "install" : true,
+      "namespace" : "export1::"
+    },
+    {
+      "cxx-module-info-dir" : "cxx-modules",
+      "destination" : "lib/cmake/export2",
+      "export-name" : "with::public_",
+      "export-prefix" : "<BINARY_DIR>/CMakeFiles/Export/28cd47cb4c96ad5cadaa3fb1b0201ae8",
+      "filesystem-export-name" : "with_c_cpublic__",
+      "install" : true,
+      "namespace" : ""
+    },
+    {
+      "cxx-module-info-dir" : "cxx-modules",
+      "destination" : "<BINARY_DIR>/lib/cmake/export1",
+      "export-name" : "with::public_",
+      "export-prefix" : "<BINARY_DIR>/lib/cmake/export1",
+      "filesystem-export-name" : "with_c_cpublic__",
+      "install" : false,
+      "namespace" : "export1::"
+    },
+    {
+      "cxx-module-info-dir" : "cxx-modules",
+      "destination" : "<BINARY_DIR>/lib/cmake/export2",
+      "export-name" : "with::public_",
+      "export-prefix" : "<BINARY_DIR>/lib/cmake/export2",
+      "filesystem-export-name" : "with_c_cpublic__",
+      "install" : false,
+      "namespace" : ""
+    }
+  ],
+  "include-dirs": [],
+  "language": "CXX",
+  "forward-modules-from-target-dirs": [],
+  "linked-target-dirs": [],
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+}