retrofitted
verb
Definitions
To add or substitute new parts or components to some device, structure etc., that were not previously available; to modernize
To fix an older version (or older versions) as part of the same process of fixing the newest version; to backport
Example: The bug was so bad that we had to retrofit our patch to the last three releases, as well as the newest release.
adjective
Definitions
Fitted or installed at a later date