On_ItemLooting not triggering

[Mythikos]

function On_ItemLooting(ItemLootEvent)
    local ply = ItemLootEvent.Looter
    local item = ItemLootEvent.Target

    if ply.IsPlayer() then
        Server.Broadcast(ply.Name.." is looting a(n)"..tostring(item))
    end
end

This hook is never fired in game. It appears as though On_ItemLooting is never called.