Index: CMakeLists.txt
--- CMakeLists.txt.orig
+++ CMakeLists.txt
@@ -1031,12 +1031,12 @@ 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()
