Having multiple .xs files in one project

Question

In my root XS file, I have another XS file that I have to do to maintain a clean project structure:

MODULE = MyModule       PACKAGE = MyPackage
# ...
INCLUDE: xs/MySubpackage.xs

Everything works fine, except that every time I edit MySubpackage.xs, I have to manually delete "MyPackage.c", because otherwise the changes are not reflected.

Is there an easy way to get ExtUtils :: MakeMaker to automatically rebuild MyModule.c every time it changes MySubpackage.xs?