diff --git a/init.lua b/init.lua
index 12869b1..4c1da0d 100644
--- a/init.lua
+++ b/init.lua
@@ -54,7 +54,11 @@ end
 
 -- usage
 local node = clone_registered("node","default:sign_wall")
-node.groups = {choppy=2,dig_immediate=2,sign=1}
+if node.legacy_wallmounted then
+	node.groups = {choppy=2,dig_immediate=2,attached_node=1,sign=1}
+else
+	node.groups = {choppy=2,dig_immediate=2,sign=1}
+end
 minetest.register_node(":default:sign_wall",  node)