How can I specify the gulpfile to use?

So I have two gulpfiles in this site I’m working on, one for the whole project which only watches and compiles sass and one inside a Foundation Emails project which is kept in a subdirectory in the project. When I try running any scripts or gulp tasks inside this Foundation subdirectory it runs the default task of the outer gulpfile. How can I make it so that when I’m in the subdirectory it only uses that gulpfile?