pulling in sass from custom modules

I'm trying to put some SASS for a custom module in that module's directory, rather than in the theme. I was hoping to use add_import_path to find it, but the sass file is ignored.

my custom module's path, relative to my theme, is
../../modules/custom/ves_newsletter

my sass file is ../../modules/custom/ves_newsletter/sass/style1.scss

I've tried both of these lines in my config.rb:
add_import_path "../../modules/custom/ves_newsletter"
add_import_path "../../modules/custom/ves_newsletter/sass"

I'm using compass watch. It doesn't notice changes to my custom file. Am I using the wrong syntax?