documentation of -M option insufficient

The description of the -M option looks like this: -M Generate dependency information suitable for use in a Makefile. (copied from http://www.haskell.org/ghc/docs/latest/html/users_guide/flag-reference.html#...) It should contain the hint that it writes this information to a Makefile. I'm thinking of something like -M writes dependency information suitable for use in a Makefile into the Makefile Is it worth filing a bug report? Marc