Symbols are missing from eps format

When I save a figure in eps format, the symbols that have no facecolor are not showing. This happened after I updated to the latest version.

Code for reproduction

import matplotlib.pyplot as plt
plt.plot([1,2,3],[2,1,3],'ko',markerfacecolor='None')
plt.plot([1,2,3],[2,1,3],'k')
plt.savefig('not_working.eps')
plt.savefig('working.eps')

I would expect empty circles (as will show if you save it as png), but they are missing when saved as eps.

Unfortunately I don't remember the last version I was using and was working before updating.

• Operating system: Windows 7
• Matplotlib version: 2.2.2
• Matplotlib backend: Qt5Agg
• Python version: 3.6.5
• Spyder version: 3.2.8

I did a batch update and didn't notice this only a week after.