diff --git a/mods/ITEMS/mcl_armor/api.lua b/mods/ITEMS/mcl_armor/api.lua
index 8d08524c6..1b9aa4f73 100644
--- a/mods/ITEMS/mcl_armor/api.lua
+++ b/mods/ITEMS/mcl_armor/api.lua
@@ -115,7 +115,7 @@ function mcl_armor.register_set(def)
 			groups[k] = v
 		end
 		local upgrade_item = nil
-		if itemstring:find("_diamond") and def._mcl_upgrade_item_material then
+		if def._mcl_upgradable and def._mcl_upgrade_item_material then
 			upgrade_item = itemstring:gsub("_[%l%d]*$",def._mcl_upgrade_item_material)
 		end