diff --git a/machines/iron_furnace.lua b/machines/iron_furnace.lua
index 1acdd17..d07c29b 100644
--- a/machines/iron_furnace.lua
+++ b/machines/iron_furnace.lua
@@ -293,6 +293,7 @@ if industrialtest.mtgAvailable then
 		return not (inv:get_list("src")[1]:get_count()>0 or inv:get_list("fuel")[1]:get_count()>0 or inv:get_list("dst")[1]:get_count()>0)
 	end
 elseif industrialtest.mclAvailable then
+	definition.groups={pickaxey=1}
 	definition.after_dig_node=function(pos,oldnode,oldmeta)
 		industrialtest.internal.mclAfterDigNode(pos,oldmeta,{"src","fuel","dst"})
 	end