Index: CMakeLists.txt
--- CMakeLists.txt.orig
+++ CMakeLists.txt
@@ -909,12 +909,12 @@ else()
 endif()
 
  # change custom.bat/sh
-if (EXISTS "${INSTALL_DIR}/${INSTALL_DIR_SCRIPT}/custom.${SCRIPT_EXT}")
-  file (READ "${INSTALL_DIR}/${INSTALL_DIR_SCRIPT}/custom.${SCRIPT_EXT}" CUSTOM_CONTENT)
+if (EXISTS "${INSTALL_DIR_SCRIPT}/custom.${SCRIPT_EXT}")
+  file (READ "${INSTALL_DIR_SCRIPT}/custom.${SCRIPT_EXT}" CUSTOM_CONTENT)
 
   set (CUSTOM_CONTENT "${CUSTOM_CONTENT} ${ADDITIONAL_CUSTOM_CONTENT}")
 
-  file (WRITE "${INSTALL_DIR}/${INSTALL_DIR_SCRIPT}/custom.${SCRIPT_EXT}" "${CUSTOM_CONTENT}")
+  file (WRITE "${INSTALL_DIR_SCRIPT}/custom.${SCRIPT_EXT}" "${CUSTOM_CONTENT}")
 else()
   OCCT_CONFIGURE_AND_INSTALL ("adm/templates/custom.${SCRIPT_EXT}.main" "custom.${SCRIPT_EXT}" "custom.${SCRIPT_EXT}" "${INSTALL_DIR_SCRIPT}")
 endif()
@@ -1156,7 +1156,7 @@ foreach (OCCT_CONFIGURATION ${CMAKE_CONFIGURATION_TYPE
 endforeach()
 # install OpenCASCADE config file with compile definitions and C/C++ flags ONLY for current configuration
 install (CODE "string (TOLOWER \"\${CMAKE_INSTALL_CONFIG_NAME}\" CMAKE_INSTALL_CONFIG_NAME_LOWER)")
-install (CODE "configure_file(\"${CMAKE_BINARY_DIR}/OpenCASCADECompileDefinitionsAndFlags-\${CMAKE_INSTALL_CONFIG_NAME_LOWER}.cmake\" \"${INSTALL_DIR}/${INSTALL_DIR_CMAKE}/OpenCASCADECompileDefinitionsAndFlags-\${CMAKE_INSTALL_CONFIG_NAME_LOWER}.cmake\" COPYONLY)")
+install (CODE "configure_file(\"${CMAKE_BINARY_DIR}/OpenCASCADECompileDefinitionsAndFlags-\${CMAKE_INSTALL_CONFIG_NAME_LOWER}.cmake\" \"${INSTALL_DIR_CMAKE}/OpenCASCADECompileDefinitionsAndFlags-\${CMAKE_INSTALL_CONFIG_NAME_LOWER}.cmake\" COPYONLY)")
 
 foreach (OCCT_MODULE ${OCCT_MODULES})
   if (BUILD_MODULE_${OCCT_MODULE})