diff --git a/Control/Monad/Random.hs b/Control/Monad/Random.hs
--- a/Control/Monad/Random.hs
+++ b/Control/Monad/Random.hs
@@ -47,13 +47,14 @@
 import Control.Monad.State
 import Control.Monad.Trans()
 import Control.Monad.Writer
+import Control.Monad.Fix
 import Control.Arrow
 import Control.Applicative
 
 -- | A monad transformer which adds a random number generator to an
 -- existing monad.
 newtype (RandomGen g) => RandT g m a = RandT (StateT g m a)
-    deriving (Functor, Monad, MonadTrans, MonadIO)
+    deriving (Functor, Monad, MonadTrans, MonadIO, MonadFix)
 
 instance (Monad m) => Applicative (RandT g m) where
   pure = return
@@ -88,7 +89,7 @@
 
 -- | A basic random monad.
 newtype Rand g a = Rand (RandT g Identity a)
-    deriving (Functor, Applicative, Monad, MonadRandom, MonadSplit g)
+    deriving (Functor, Applicative, Monad, MonadRandom, MonadSplit g, MonadFix)
 
 -- | Evaluate a random computation using the generator @g@.  Note that the
 -- generator @g@ is not returned, so there's no way to recover the
diff --git a/MonadRandom.cabal b/MonadRandom.cabal
--- a/MonadRandom.cabal
+++ b/MonadRandom.cabal
@@ -1,6 +1,6 @@
 Name:                MonadRandom
 Build-type:          Simple
-Version:             0.1.4
+Version:             0.1.5
 Synopsis:            Random-number generation monad.
 Description:         Support for computations which consume random values.
 License:             OtherLicense