diff --git a/Control/Monad/CryptoRandom.hs b/Control/Monad/CryptoRandom.hs
--- a/Control/Monad/CryptoRandom.hs
+++ b/Control/Monad/CryptoRandom.hs
@@ -27,7 +27,7 @@
   ) where
 
 import Control.Applicative
-import Control.Arrow (right, left)
+import Control.Arrow (right, left, first)
 import Control.Monad (liftM)
 import Control.Monad.Cont
 import Control.Monad.Error
@@ -255,6 +255,9 @@
 instance CRandomR Int64 where
   crandomR = crandomR_Num
   {-# INLINE crandomR #-}
+
+instance CRandom Bool where
+  crandom g = first (toEnum . fromIntegral) `fmap` crandomR (0::Word8,1) g
 
 crandomR_Num :: (Integral a, CryptoRandomGen g) => (a,a) -> g -> Either GenError (a,g)
 crandomR_Num (low, high) g
diff --git a/monadcryptorandom.cabal b/monadcryptorandom.cabal
--- a/monadcryptorandom.cabal
+++ b/monadcryptorandom.cabal
@@ -1,5 +1,5 @@
 name:           monadcryptorandom
-version:        0.5.1
+version:        0.5.2
 license:        BSD3
 license-file:   LICENSE
 copyright:      Thomas DuBuisson <thomas.dubuisson@gmail.com>