Technologies are disclosed herein for updating a firmware file system (FFS) file by preserving the original FFS file in its current firmware volume and then storing an updated version of the original FFS file in a firmware volume for updated FFS files. The updated FFS file may be stored in the firmware volume for updated FFS files referenced to the same FFS file identifier as the original FFS file. During boot-up of a system incorporating the updated firmware, the firmware volume for updated FFS files may be accessed to determine if an updated version of any FFS files are present. If updated FFS files are present, then those updated FFS files may be executed, rather than the original FFS files.