diff --git a/semigroups.cabal b/semigroups.cabal
--- a/semigroups.cabal
+++ b/semigroups.cabal
@@ -1,6 +1,6 @@
 name:          semigroups
 category:      Algebra, Data, Data Structures, Math
-version:       0.15.4
+version:       0.16
 license:       BSD3
 cabal-version: >= 1.10
 license-file:  LICENSE
@@ -83,7 +83,7 @@
 
   build-depends:
     base >= 2   && < 5,
-    nats >= 0.1 && < 1
+    nats >= 0.1 && < 2
 
   if impl(ghc >= 7.4 && < 7.5)
     build-depends: ghc-prim
diff --git a/src/Data/Semigroup.hs b/src/Data/Semigroup.hs
--- a/src/Data/Semigroup.hs
+++ b/src/Data/Semigroup.hs
@@ -85,7 +85,7 @@
 import Data.Foldable
 import Data.Traversable
 import Data.List.NonEmpty
-import Numeric.Natural.Internal
+import Numeric.Natural
 
 #ifdef MIN_VERSION_deepseq
 import Control.DeepSeq (NFData(..))
@@ -170,17 +170,17 @@
   --
   -- See also 'timesN'.
 
-  times1p :: Whole n => n -> a -> a
+  times1p :: Natural -> a -> a
   times1p y0 x0 = f x0 (1 Prelude.+ y0)
     where
       f x y
         | even y = f (x <> x) (y `quot` 2)
         | y == 1 = x
-        | otherwise = g (x <> x) (unsafePred y  `quot` 2) x
+        | otherwise = g (x <> x) (pred y  `quot` 2) x
       g x y z
         | even y = g (x <> x) (y `quot` 2) z
         | y == 1 = x <> z
-        | otherwise = g (x <> x) (unsafePred y `quot` 2) (x <> z)
+        | otherwise = g (x <> x) (pred y `quot` 2) (x <> z)
   {-# INLINE times1p #-}
 
 -- | A generalization of 'Data.List.cycle' to an arbitrary 'Semigroup'.
@@ -659,9 +659,9 @@
 -- > timesN n a = a <> a <> ... <> a  -- using <> (n-1) times
 --
 -- Implemented using 'times1p'.
-timesN :: (Whole n, Monoid a) => n -> a -> a
+timesN :: Monoid a => Natural -> a -> a
 timesN n x | n == 0    = mempty
-           | otherwise = unwrapMonoid . times1p (unsafePred n) . WrapMonoid $ x
+           | otherwise = unwrapMonoid . times1p (pred n) . WrapMonoid $ x
 {-# INLINE timesN #-}