@@ -78,8 +78,22 @@
 		meta:mark_as_private('sorcery:attune')
 	end;
 	pair = function(reciprocal,src,dest)
 		local d, code = sorcery.attunement.get(src)
+		local gdef = function(n)
+			local m = minetest.registered_nodes[minetest.get_node(n).name]
+			if m and m._sorcery and m._sorcery.attune then
+				return m._sorcery.attune
+			end
+			return nil
+		end
+
+		local dsrc, dtgt = gdef(src), gdef(tgt)
+		if not (dsrc and dtgt) then return nil end
+
+		if not (dsrc.source and dtgt.target) then return nil end
+		if dtgt.accepts ~= dsrc.class then return nil end
+		
 		if reciprocal or not d then
 			code = math.random(0,65536)
 			sorcery.attunement.set(src, {
 				code = code;