Shows unresolved reference for resolved reference in PyQt5

On Win7 64bit with Python 3.5.1 (64bit) and PyQt5 (Qt 5.6) and PyCharm Community 2016.1.4 I get the "unresolved reference" warning in PyCharm for

from PyQt5 import QtWidgets

while if I run the script it runs just fine. Re-indexing doesn't help but funnily this works:

import PyQt5.QtWidgets

without warning (and runs too). PyCharm seems to get something wrong.