Decaying Hex does not work with Blasphemy

The Decaying Hex support gem which applies a DoT on cursed enemies does not work with Blasphemy, which makes your curses an aura. I was using Decaying Hex on Flammability, then when I got Blasphemy and transferred them over I noticed this.

I don't know if this is intended or not, but I shouldn't be able to socket Decaying Hex to Blasphemy if they do not work together.