PILImageReader doesn't like writing 16-bit images

Setting the reader to output 16-bit images results in a ValueError, saying there is not enough image data. I haven't found. Below is the full traceback:

Traceback (most recent call last):
  File "./main.py", line 51, in <module>
    main()
  File "./main.py", line 46, in main
    img = reader(terr)
  File "/home/solarliner/Documents/Projects/Desktop/TerrainLib/terrainlib/readers/image.py", line 50, in __call__
    return Image.fromarray(numpy.array(mult_arr, dtype=dtype), mode)
  File "/home/solarliner/.local/share/virtualenvs/TerrainLib-bHmQXCEV/lib/python3.6/site-packages/PIL/Image.py", line 2450, in fromarray
    return frombuffer(mode, size, obj, "raw", rawmode, 0, 1)
  File "/home/solarliner/.local/share/virtualenvs/TerrainLib-bHmQXCEV/lib/python3.6/site-packages/PIL/Image.py", line 2403, in frombuffer
    return frombytes(mode, size, data, decoder_name, args)
  File "/home/solarliner/.local/share/virtualenvs/TerrainLib-bHmQXCEV/lib/python3.6/site-packages/PIL/Image.py", line 2336, in frombytes
    im.frombytes(data, decoder_name, args)
  File "/home/solarliner/.local/share/virtualenvs/TerrainLib-bHmQXCEV/lib/python3.6/site-packages/PIL/Image.py", line 788, in frombytes
    raise ValueError("not enough image data")
ValueError: not enough image data