Can I exclude .gitmodules (or any file) from git-format-patch?

Is there a way I can get git-format-patch to ignore specific files?
Specifically, I want it to ignore .gitmodules.  This file is changed
whenever a submodule is added or removed, but I don't want git
format-patch to pick it up.  I already specify --ignore-submodules, so
I was expecting format-patch to ignore *everything* related to
sobmodules.

Perhaps --ignore-submodules should also ignore any changes to .gitmodules?

(Why is .gitmodules not in the .git directory, anyway?)

-- 
Timur Tabi
Linux kernel developer at Freescale