diff --git a/exact-real.cabal b/exact-real.cabal
--- a/exact-real.cabal
+++ b/exact-real.cabal
@@ -1,5 +1,5 @@
 name:         exact-real
-version:      0.12.1
+version:      0.12.2
 synopsis:     Exact real arithmetic
 description:
   A type to represent exact real numbers using fast binary Cauchy sequences.
@@ -17,7 +17,7 @@
   readme.md
   stack.yaml
 cabal-version:       >=1.10
-tested-with: GHC >= 7.10 && < 8
+tested-with: GHC >= 7.10 && <= 8.0.1
 
 source-repository head
   type: git
@@ -29,9 +29,9 @@
     Data.CReal.Converge
     Data.CReal.Internal
   build-depends:
-    base        >= 4.8 && < 4.9,
+    base        >= 4.8 && < 4.10,
     integer-gmp           < 1.1.0.0,
-    memoize     >= 0.7 && < 0.8,
+    memoize     >= 0.7 && < 0.9,
     random      >= 1.0 && < 1.2
   hs-source-dirs:
     src
diff --git a/src/Data/CReal/Converge.hs b/src/Data/CReal/Converge.hs
--- a/src/Data/CReal/Converge.hs
+++ b/src/Data/CReal/Converge.hs
@@ -3,6 +3,7 @@
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE ConstrainedClassMethods #-}
 
 -- | The Converge type class.
 module Data.CReal.Converge
diff --git a/src/Data/CReal/Internal.hs b/src/Data/CReal/Internal.hs
--- a/src/Data/CReal/Internal.hs
+++ b/src/Data/CReal/Internal.hs
@@ -75,10 +75,10 @@
 
 default ()
 
--- | The type CReal represents a fast binary Cauchy sequence. This is
--- a Cauchy sequence with the invariant that the pth element will be within
--- 2^-p of the true value. Internally this sequence is represented as
--- a function from Ints to Integers.
+-- | The type CReal represents a fast binary Cauchy sequence. This is a Cauchy
+-- sequence with the invariant that the pth element divided by 2^p will be
+-- within 2^-p of the true value. Internally this sequence is represented as a
+-- function from Ints to Integers.
 newtype CReal (n :: Nat) = CR (Int -> Integer)
 
 -- | 'crMemoize' takes a fast binary Cauchy sequence and returns a CReal