Index: tools/build/CMake/BoostCore.cmake
===================================================================
--- tools/build/CMake/BoostCore.cmake	(revision 47006)
+++ tools/build/CMake/BoostCore.cmake	(working copy)
@@ -191,10 +191,41 @@
       ${ULIBNAME})
 
     if(THIS_PROJECT_HEADERS)
+      list(APPEND ${LIBNAME}-modularize-commands
+        COMMAND "${CMAKE_COMMAND}" -E remove_directory
+        "${Boost_SOURCE_DIR}/libs/${libname}/include"
+        COMMAND "${CMAKE_COMMAND}" -E make_directory
+        "${Boost_SOURCE_DIR}/libs/${libname}/include/boost"
+        )
+      foreach(item ${THIS_PROJECT_HEADERS})
+        if(EXISTS "${Boost_SOURCE_DIR}/boost/${item}")
+          if(IS_DIRECTORY "${Boost_SOURCE_DIR}/boost/${item}")
+            list(APPEND ${LIBNAME}-modularize-commands
+              COMMAND "${CMAKE_COMMAND}" -E copy_directory
+              "${Boost_SOURCE_DIR}/boost/${item}"
+              "${Boost_SOURCE_DIR}/libs/${libname}/include/boost/${item}"
+              COMMAND "${CMAKE_COMMAND}" -E remove_directory
+              "${Boost_SOURCE_DIR}/boost/${item}"
+              )
+          else(IS_DIRECTORY "${Boost_SOURCE_DIR}/boost/${item}")
+            list(APPEND ${LIBNAME}-modularize-commands
+              COMMAND "${CMAKE_COMMAND}" -E copy
+              "${Boost_SOURCE_DIR}/boost/${item}"
+              "${Boost_SOURCE_DIR}/libs/${libname}/include/boost/${item}"
+              COMMAND "${CMAKE_COMMAND}" -E remove
+              "${Boost_SOURCE_DIR}/boost/${item}"
+              )
+          endif(IS_DIRECTORY "${Boost_SOURCE_DIR}/boost/${item}")
+        else(EXISTS "${Boost_SOURCE_DIR}/boost/${item}")
+          MESSAGE(FATAL_ERROR
+            "Source file '${Boost_SOURCE_DIR}/boost/${item}' not available."
+            "Modularization might have moved it, please update your boost directory."
+            )
+        endif(EXISTS "${Boost_SOURCE_DIR}/boost/${item}")
+      endforeach(item)
+
       add_custom_target(${LIBNAME}-modularize
-	COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_SOURCE_DIR}/tools/build/CMake/modularize.py 
-	${Boost_SOURCE_DIR}/boost ${THIS_PROJECT_HEADERS} ${Boost_SOURCE_DIR}/libs/${libname}/include/boost
-	WORKING_DIRECTORY ${Boost_SOURCE_DIR}/boost
+        ${${LIBNAME}-modularize-commands}
 	COMMENT "Modularizing ${LIBNAME} headers to project-local dir from monolithic boost dir"
 	)
       add_dependencies(modularize ${LIBNAME}-modularize)