AttributeError when unpickling an object

I'm trying to pickle an instance of a class in one module, and unpickle it in another.

Here's where I pickle:

import cPickle

def pickleObject():
    object = Foo()
    savefile = open('path/to/file', 'w')
    cPickle.dump(object, savefile, cPickle.HIGHEST_PROTOCOL)


class Foo(object):
    (...)

and here's where I try to unpickle:

savefile = open('path/to/file', 'r')
object = cPickle.load(savefile)

On that second line, I get AttributeError: 'module' object has no attribute 'Foo'

Anyone see what I'm doing wrong?