diff --git a/items.lua b/items.lua
index 6c4433c..b9a5179 100644
--- a/items.lua
+++ b/items.lua
@@ -39,10 +39,10 @@ end
 
 local function add_aliases(old, new)
 	minetest.register_alias("nether:"..old, "hell:"..new)
-	minetest.register_alias("nether"..":stair_"..old, "hell"..":stair_"..new)
-	minetest.register_alias("nether"..":slab_"..old, "hell"..":slab_"..new)
-	minetest.register_alias("stairs:"..":stair_"..old, "hell"..":stair_"..new)
-	minetest.register_alias("stairs:"..":slab_"..old, "hell"..":slab_"..new)
+	minetest.register_alias("nether:stair_"..old, "hell:stair_"..new)
+	minetest.register_alias("nether:slab_"..old, "hell:slab_"..new)
+	minetest.register_alias("stairs:stair_"..old, "hell:stair_"..new)
+	minetest.register_alias("stairs:slab_"..old, "hell:slab_"..new)
 end
 
 --[[