diff --git a/non-negative.cabal b/non-negative.cabal
--- a/non-negative.cabal
+++ b/non-negative.cabal
@@ -1,5 +1,5 @@
 Name:             non-negative
-Version:          0.0.3
+Version:          0.0.4
 License:          GPL
 License-File:     LICENSE
 Author:           Henning Thielemann <haskell@henning-thielemann.de>
@@ -25,10 +25,11 @@
   default:     False
 
 Library
+  Build-Depends: QuickCheck >= 1.0 && <2
   If flag(splitBase)
-    Build-Depends: base >= 2, QuickCheck
+    Build-Depends: base >= 2
   Else
-    Build-Depends: base >= 1.0 && < 2, QuickCheck
+    Build-Depends: base >= 1.0 && < 2
 
   GHC-Options:      -Wall
   Hs-Source-Dirs:   src
diff --git a/src/Numeric/NonNegative/Chunky.hs b/src/Numeric/NonNegative/Chunky.hs
--- a/src/Numeric/NonNegative/Chunky.hs
+++ b/src/Numeric/NonNegative/Chunky.hs
@@ -16,7 +16,6 @@
 which allows for co-recursive merges.
 -}
 module Numeric.NonNegative.Chunky
-   (T, fromChunks, fromNumber, toNumber, normalize, isNull, isPositive, ) where
+   (T, fromChunks, fromNumber, toChunks, toNumber, zero, normalize, isNull, isPositive, ) where
 
 import Numeric.NonNegative.ChunkyPrivate
-   (T, fromChunks, fromNumber, toNumber, normalize, isNull, isPositive, )
diff --git a/src/Numeric/NonNegative/ChunkyPrivate.hs b/src/Numeric/NonNegative/ChunkyPrivate.hs
--- a/src/Numeric/NonNegative/ChunkyPrivate.hs
+++ b/src/Numeric/NonNegative/ChunkyPrivate.hs
@@ -11,7 +11,8 @@
 we cannot use that in the NumericPrelude.
 -}
 module Numeric.NonNegative.ChunkyPrivate
-   (T, fromChunks, fromNumber, toNumber, normalize, isNull, isPositive,
+   (T, fromChunks, fromNumber, toChunks, toNumber,
+    zero, normalize, isNull, isPositive,
     fromChunksUnsafe, toChunksUnsafe, ) where
 
 import qualified Numeric.NonNegative.Class as NonNeg
@@ -40,6 +41,13 @@
 fromNumber :: NonNeg.C a => a -> T a
 fromNumber = fromChunks . (:[])
 
+
+{- |
+This routine exposes the inner structure of the lazy number.
+-}
+toChunks :: T a -> [a]
+toChunks = decons
+
 toNumber :: NonNeg.C a => T a -> a
 toNumber =  sum . decons
 
@@ -53,6 +61,9 @@
 lift2 :: ([a] -> [a] -> [a]) -> (T a -> T a -> T a)
 lift2 f (Cons x) (Cons y) = Cons $ f x y
 
+zero :: T a
+zero = Cons []
+
 {- |
 Remove zero chunks.
 -}
@@ -154,8 +165,12 @@
 fromChunksUnsafe = Cons
 
 {- |
-This routine exposes the inner structure of the lazy number,
-and I think it should be used with care.
+This routine exposes the inner structure of the lazy number
+and is actually the same as 'toChunks'.
+It was considered dangerous,
+but you can observe the lazy structure
+in tying-the-knot applications anyway.
+So the explicit revelation of the chunks seems not to be worse.
 -}
 toChunksUnsafe :: T a -> [a]
 toChunksUnsafe = decons