django not found

I am using PyCharm 3.4.1.  I have set up a project to use a local variant of Django located at /prog/django.  I've assigned Django support to the project using:  File > Settings > Django > Enable Django Support, and I've set the Django Project Root to /prog/django.  However, the PyCharm editor will not recognize "django" in e.g. from django import forms.  

How do I get the editor to recognize Django?  In previous versions of PyCharm there was a project path setting, but no more.

Thanks for any help.

Alex