`pip install cupy` is not correcly installing cupyx

I’m installing cupy on a windows 10 machine running 3.7.3 and cuda 9.0. I’ve installed cupy successfully using pip install cupy-cuda90, in that the installation ends without error and I can use basic cupy functions. But when I try to get into the scipy packages, I find that some of them aren’t installing on my machine (ex: scipy.ndimage.filters) and none of the scipy modules can be loaded.

 >>> cp.cupyx.scipy.ndimage
  AttributeError: module 'cupyx.scipy' has no attribute 'ndimage'

I’m also getting this error:

     >>> import cupy.cupyx.scipy as s
     ModuleNotFoundError: No module named 'cupy.cupyx'

but this works:

      from cupy import cupyx
      from cupyx import scipy