diff --git a/src/GoodList.hs b/src/GoodList.hs
index 37b50d9..b806f91 100644
--- a/src/GoodList.hs
+++ b/src/GoodList.hs
@@ -53,9 +53,9 @@ snoc (Singleton a)    = Multiple a Empty
 snoc (Multiple a b c) = Multiple a (b `snoc` c)
 
 append :: GoodList a -> GoodList a -> GoodList a
-append  Empty            ys              = ys
-append (Singleton x)     ys              = cons x ys
-append (Multiple a b c)  ys              = cons a . append b $ cons c ys
+append  Empty           = id
+append (Singleton x)    = cons x
+append (Multiple a b c) = cons a . append b . cons c
 
 join :: GoodList (GoodList a) -> GoodList a
 join Empty = Empty