diff --git a/Data/BinaryList.hs b/Data/BinaryList.hs
--- a/Data/BinaryList.hs
+++ b/Data/BinaryList.hs
@@ -133,9 +133,9 @@
     go i (ListNode n l r) =
       let m = 2^(n-1)
       in  if i < m
-             then ListNode (go i l)          r
-             else ListNode       l (go (i-m) r)
-    go 0 (ListEnd x) = ListEnd y
+             then ListNode n (go i l)          r
+             else ListNode n       l (go (i-m) r)
+    go 0 (ListEnd _) = ListEnd y
     go _ e = e
 
 -- | /O(1)/. Append two binary lists. This is only possible
diff --git a/binary-list.cabal b/binary-list.cabal
--- a/binary-list.cabal
+++ b/binary-list.cabal
@@ -1,5 +1,5 @@
 name:                binary-list
-version:             0.3.4.0
+version:             0.3.4.1
 synopsis:            Lists of size length a power of two.
 description:         Implementation of lists whose number of elements is a
                      power of two. Binary lists have this property by definition,