update-rc.d my-program defaults 20 80 update-rc.d my-program defaults start 20 2 3 4 5 . stop 80 0 1 6 .
Support for run levels in "start" and "stop" subcommands was dropped from update-rc.d by Roger Leigh in 2013. You'll find that the command has been warning you about using explicit run levels in start and stop that don't match the header in the script file since at least 2009. The sole source of information about applicable run levels is now the header in the script file. At the very minimum, switch to only using the header-based way of doing things. Better: switch to only using "defaults", and not "start" and "stop" at all. Note also that "defaults" now ignores any arguments given to it, that having been dropped in 2013 as well. Non-dependency based van Smoorenbug rc script organization has been removed from update-rc.d. So best: just use "defaults", use it without arguments, and supply a (correct) header.
* http://anonscm.debian.org/cgit/collab-maint/sysvinit.git/commit/?id=6323a1e4eb39ed1c050b1e74b6baef92dcfde4b1 * http://anonscm.debian.org/cgit/collab-maint/sysvinit.git/commit/?id=23aa96526e2cfc11e29507547dd38c1ff0c7e804
Note, in all of the fiddling with the sysv-rc package that you are all doing in this thread, that update-rc.d is no longer part of that package and has not been since 2015.
* http://anonscm.debian.org/cgit/collab-maint/sysvinit.git/commit/?id=9b3afdb93ab6d1f73c3ae50c0f816b915665b1e2