PIL.Image Closing error using Matplotlib imread()

I'm using imread() from the matplotlib.pyplot library because I want to plot my scatter plots on top of an image:

import matplotlib.pyplot as plt
import logging

logging.basicConfig(level=logging.DEBUG)
logger = logging.getLogger(__name__)
model_image = plt.imread('data/img1.jpg')

Everything works fine. However, when I use the logger of the standard python lib, it prints a DEBUG error:

DEBUG:PIL.Image:Error closing: 'NoneType' object has no attribute 'close'

This bothers me. Am I doing something wrong, our is it matplotlib fault?

FYI matplotlib version: 2.1.0