diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+### 0.1.3.1
+
+* Added `withFrozen` function.
+
 ### 0.1.3.0
 
 * Use [entropy](http://hackage.haskell.org/package/entropy) package for
diff --git a/pcg-random.cabal b/pcg-random.cabal
--- a/pcg-random.cabal
+++ b/pcg-random.cabal
@@ -1,5 +1,5 @@
 name:                pcg-random
-version:             0.1.3.0
+version:             0.1.3.1
 synopsis:            Haskell bindings to the PCG random number generator.
 description:
   PCG is a family of simple fast space-efficient statistically good
diff --git a/src/System/Random/PCG.hs b/src/System/Random/PCG.hs
--- a/src/System/Random/PCG.hs
+++ b/src/System/Random/PCG.hs
@@ -3,8 +3,9 @@
 {-# LANGUAGE DeriveGeneric              #-}
 {-# LANGUAGE FlexibleInstances          #-}
 {-# LANGUAGE ForeignFunctionInterface   #-}
-{-# LANGUAGE TypeFamilies               #-}
 {-# LANGUAGE MultiParamTypeClasses      #-}
+{-# LANGUAGE RankNTypes                 #-}
+{-# LANGUAGE TypeFamilies               #-}
 #if __GLASGOW_HASKELL__ >= 707
 {-# LANGUAGE RoleAnnotations            #-}
 #endif
@@ -36,7 +37,8 @@
 module System.Random.PCG
   ( -- * Generator
     Gen, GenIO, GenST
-  , create, createSystemRandom, initialize, withSystemRandom
+  , create, createSystemRandom, initialize
+  , withSystemRandom, withFrozen
 
     -- * Getting random numbers
   , Variate (..)
@@ -63,10 +65,9 @@
   , uniformBF, uniformBD, uniformBBool
   ) where
 
-#if __GLASGOW_HASKELL__ < 710
 import Control.Applicative
-#endif
 import Control.Monad.Primitive
+import Control.Monad.ST
 import Data.Data
 import Foreign
 import GHC.Generics
@@ -172,6 +173,11 @@
   w1 <- sysRandom
   w2 <- sysRandom
   initialize w1 w2 >>= f
+
+-- | Run an action with a frozen generator, returning the result and the
+--   new frozen generator.
+withFrozen :: FrozenGen -> (forall s. Gen s -> ST s a) -> (a, FrozenGen)
+withFrozen s f = runST $ restore s >>= \g -> liftA2 (,) (f g) (save g)
 
 -- | Seed a PRNG with data from the system's fast source of pseudo-random
 -- numbers. All the caveats of 'withSystemRandom' apply here as well.
diff --git a/src/System/Random/PCG/Class.hs b/src/System/Random/PCG/Class.hs
--- a/src/System/Random/PCG/Class.hs
+++ b/src/System/Random/PCG/Class.hs
@@ -416,7 +416,7 @@
 
 -- IO randoms
 
--- | Generate a random number using 'System.Entropy'.
+-- | Generate a random number using "System.Entropy".
 --
 --   Use RDRAND if available and XOR with @\/dev\/urandom@ on Unix and
 --   CryptAPI on Windows. This entropy is considered cryptographically
diff --git a/src/System/Random/PCG/Fast.hs b/src/System/Random/PCG/Fast.hs
--- a/src/System/Random/PCG/Fast.hs
+++ b/src/System/Random/PCG/Fast.hs
@@ -3,9 +3,10 @@
 {-# LANGUAGE DeriveGeneric              #-}
 {-# LANGUAGE FlexibleInstances          #-}
 {-# LANGUAGE ForeignFunctionInterface   #-}
-{-# LANGUAGE TypeFamilies               #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE MultiParamTypeClasses      #-}
+{-# LANGUAGE RankNTypes                 #-}
+{-# LANGUAGE TypeFamilies               #-}
 #if __GLASGOW_HASKELL__ >= 707
 {-# LANGUAGE RoleAnnotations            #-}
 #endif
@@ -38,7 +39,8 @@
 module System.Random.PCG.Fast
   ( -- * Gen
     Gen, GenIO, GenST
-  , create, createSystemRandom, initialize, withSystemRandom
+  , create, createSystemRandom, initialize
+  , withSystemRandom, withFrozen
 
     -- * Getting random numbers
   , Variate (..)
@@ -64,10 +66,9 @@
   , uniformBF, uniformBD, uniformBBool
   ) where
 
-#if __GLASGOW_HASKELL__ < 710
 import Control.Applicative
-#endif
 import Control.Monad.Primitive
+import Control.Monad.ST
 import Data.Data
 import Foreign
 import GHC.Generics
@@ -152,6 +153,11 @@
 withSystemRandom f = do
   w <- sysRandom
   initialize w >>= f
+
+-- | Run an action with a frozen generator, returning the result and the
+--   new frozen generator.
+withFrozen :: FrozenGen -> (forall s. Gen s -> ST s a) -> (a, FrozenGen)
+withFrozen s f = runST $ restore s >>= \g -> liftA2 (,) (f g) (save g)
 
 -- | Seed a PRNG with data from the system's fast source of pseudo-random
 -- numbers. All the caveats of 'withSystemRandom' apply here as well.
diff --git a/src/System/Random/PCG/Single.hs b/src/System/Random/PCG/Single.hs
--- a/src/System/Random/PCG/Single.hs
+++ b/src/System/Random/PCG/Single.hs
@@ -3,9 +3,10 @@
 {-# LANGUAGE DeriveGeneric              #-}
 {-# LANGUAGE FlexibleInstances          #-}
 {-# LANGUAGE ForeignFunctionInterface   #-}
-{-# LANGUAGE TypeFamilies               #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE MultiParamTypeClasses      #-}
+{-# LANGUAGE RankNTypes                 #-}
+{-# LANGUAGE TypeFamilies               #-}
 #if __GLASGOW_HASKELL__ >= 707
 {-# LANGUAGE RoleAnnotations            #-}
 #endif
@@ -36,7 +37,8 @@
 module System.Random.PCG.Single
   ( -- * Gen
     Gen, GenIO, GenST
-  , create, createSystemRandom, initialize, withSystemRandom
+  , create, createSystemRandom, initialize
+  , withSystemRandom, withFrozen
 
     -- * Getting random numbers
   , Variate (..)
@@ -63,10 +65,9 @@
   , uniformBF, uniformBD, uniformBBool
   ) where
 
-#if __GLASGOW_HASKELL__ < 710
 import Control.Applicative
-#endif
 import Control.Monad.Primitive
+import Control.Monad.ST
 import Data.Data
 import Foreign
 import GHC.Generics
@@ -145,6 +146,11 @@
 --   systems, time otherwise).
 withSystemRandom :: (GenIO -> IO a) -> IO a
 withSystemRandom f = sysRandom >>= initialize >>= f
+
+-- | Run an action with a frozen generator, returning the result and the
+--   new frozen generator.
+withFrozen :: FrozenGen -> (forall s. Gen s -> ST s a) -> (a, FrozenGen)
+withFrozen s f = runST $ restore s >>= \g -> liftA2 (,) (f g) (save g)
 
 -- | Seed a PRNG with data from the system's fast source of pseudo-random
 --   numbers. All the caveats of 'withSystemRandom' apply here as well.