Hi all, This is a warning for a planned change to np.memmap in https://github.com/numpy/numpy/pull/7406. The return values of ufuncs and fancy slices of a memmap will now be plain ndarrays, since those return values don't point to mem-mapped memory. There is a possibility that if you are subclassing memmap using multiple inheritance something may break. We don't think anyone will be affected, but please reply if it does affect you. Allan