Dark Effigy + Cast on Minion Death

I have been trying to run a contagion + Minion build for a bit now and have been wondering why I couldn't do Cast on Minion Death + Dark Effigy. It was kind of shocking when I went to throw those two together and found out Dark Effigy seems to be treated the same way as other Minion skills, despite it being a Totem

Is this intended?