diff --git a/Control/Monad/CryptoRandom.hs b/Control/Monad/CryptoRandom.hs
--- a/Control/Monad/CryptoRandom.hs
+++ b/Control/Monad/CryptoRandom.hs
@@ -351,7 +351,7 @@
 evalCRandT m g = liftM (right fst) (runCRandT m g)
 {-# INLINE evalCRandT #-}
 
-runCRand :: CRand g GenError a -> g -> Either GenError (a, g)
+runCRand :: (ContainsGenError e) => CRand g e a -> g -> Either e (a, g)
 runCRand m = runIdentity . runCRandT m
 {-# INLINE runCRand #-}
 
diff --git a/monadcryptorandom.cabal b/monadcryptorandom.cabal
--- a/monadcryptorandom.cabal
+++ b/monadcryptorandom.cabal
@@ -1,5 +1,5 @@
 name:           monadcryptorandom
-version:        0.6
+version:        0.6.1
 license:        BSD3
 license-file:   LICENSE
 copyright:      Thomas DuBuisson <thomas.dubuisson@gmail.com>