Sion W ability passive not triggering in jungle.

Sion 's W, Soul Furnace's passive is "Sion permanently gains 2 bonus health whenever he kills a** unit, increased to 10 against large units** and champion kills and assists." This ability's passive has not triggered for me once in the last game in the jungle. With over 97 cs, I had only 100 something bonus health because it only counted lane minions and kill/assist. I'm guessing this is a bug as the wording implies jungle mob, which are unit as well but half way through the game I tested it and I did not gain any health when killing mobs, trying with every jungle mob and none of them gave bonus health. This should be fixed as soon as possible as it makes jungle Sion impossible since his tankiness comes largely from his passive.