diff --git a/game/modules/tome/data/damage_types.lua b/game/modules/tome/data/damage_types.lua
index 64bb9cd144113f1946161fe33472a6d8147edae5..0901f6cbaad45ac2dd4a083d8e6a7e0070816c7e 100644
--- a/game/modules/tome/data/damage_types.lua
+++ b/game/modules/tome/data/damage_types.lua
@@ -22,7 +22,7 @@ setDefaultProjector(function(src, x, y, type, dam, tmp, no_martyr)
 	if not game.level.map:isBound(x, y) then return 0 end
 
 	local add_dam = 0
-	if src:attr("all_damage_convert") then
+	if src:attr("all_damage_convert") and src.all_damage_convert ~= type then
 		local ndam = dam * src.all_damage_convert_percent / 100
 		dam = dam - ndam
 		local nt = src.all_damage_convert