diff --git a/deferred-folds.cabal b/deferred-folds.cabal
--- a/deferred-folds.cabal
+++ b/deferred-folds.cabal
@@ -1,7 +1,7 @@
 name:
   deferred-folds
 version:
-  0.6.1
+  0.6.2
 category:
   Folding
 synopsis:
diff --git a/library/DeferredFolds/Prelude.hs b/library/DeferredFolds/Prelude.hs
--- a/library/DeferredFolds/Prelude.hs
+++ b/library/DeferredFolds/Prelude.hs
@@ -7,16 +7,68 @@
 
 -- base
 -------------------------
-import Prelude as Exports hiding ((<>))
-import Foreign as Exports hiding (void)
+import Control.Applicative as Exports
+import Control.Arrow as Exports
+import Control.Category as Exports
+import Control.Concurrent as Exports
+import Control.Exception as Exports
+import Control.Monad as Exports hiding (mapM_, sequence_, forM_, msum, mapM, sequence, forM)
+import Control.Monad.IO.Class as Exports
+import Control.Monad.Fix as Exports hiding (fix)
+import Control.Monad.ST as Exports
+import Data.Bits as Exports
 import Data.Bool as Exports
-import Data.Monoid as Exports hiding ((<>), First(..), Last(..))
-import Data.Semigroup as Exports
+import Data.Char as Exports
+import Data.Coerce as Exports
+import Data.Complex as Exports
+import Data.Data as Exports
+import Data.Dynamic as Exports
+import Data.Either as Exports
+import Data.Fixed as Exports
 import Data.Foldable as Exports
+import Data.Function as Exports hiding (id, (.))
+import Data.Functor as Exports
 import Data.Functor.Identity as Exports
+import Data.Int as Exports
+import Data.IORef as Exports
+import Data.Ix as Exports
+import Data.List as Exports hiding (sortOn, isSubsequenceOf, uncons, concat, foldr, foldl1, maximum, minimum, product, sum, all, and, any, concatMap, elem, foldl, foldr1, notElem, or, find, maximumBy, minimumBy, mapAccumL, mapAccumR, foldl')
+import Data.Maybe as Exports
+import Data.Monoid as Exports hiding (Last(..), First(..))
+import Data.Ord as Exports
+import Data.Proxy as Exports
+import Data.Ratio as Exports
+import Data.STRef as Exports
+import Data.String as Exports
 import Data.Traversable as Exports
-import Control.Applicative as Exports
-import Control.Monad as Exports
+import Data.Tuple as Exports
+import Data.Unique as Exports
+import Data.Version as Exports
+import Data.Word as Exports
+import Debug.Trace as Exports
+import Foreign.ForeignPtr as Exports
+import Foreign.Ptr as Exports
+import Foreign.StablePtr as Exports
+import Foreign.Storable as Exports hiding (sizeOf, alignment)
+import GHC.Conc as Exports hiding (withMVar, threadWaitWriteSTM, threadWaitWrite, threadWaitReadSTM, threadWaitRead)
+import GHC.Exts as Exports (lazy, inline, sortWith, groupWith)
+import GHC.Generics as Exports (Generic)
+import GHC.IO.Exception as Exports
+import Numeric as Exports
+import Prelude as Exports hiding (concat, foldr, mapM_, sequence_, foldl1, maximum, minimum, product, sum, all, and, any, concatMap, elem, foldl, foldr1, notElem, or, mapM, sequence, id, (.))
+import System.Environment as Exports
+import System.Exit as Exports
+import System.IO as Exports
+import System.IO.Error as Exports
+import System.IO.Unsafe as Exports
+import System.Mem as Exports
+import System.Mem.StableName as Exports
+import System.Timeout as Exports
+import Text.ParserCombinators.ReadP as Exports (ReadP, ReadS, readP_to_S, readS_to_P)
+import Text.ParserCombinators.ReadPrec as Exports (ReadPrec, readPrec_to_P, readP_to_Prec, readPrec_to_S, readS_to_Prec)
+import Text.Printf as Exports (printf, hPrintf)
+import Text.Read as Exports (Read(..), readMaybe, readEither)
+import Unsafe.Coerce as Exports
 
 -- containers
 -------------------------
diff --git a/library/DeferredFolds/UnfoldM.hs b/library/DeferredFolds/UnfoldM.hs
--- a/library/DeferredFolds/UnfoldM.hs
+++ b/library/DeferredFolds/UnfoldM.hs
@@ -27,6 +27,7 @@
 
 instance Monad m => Monad (UnfoldM m) where
   return = pure
+  {-# INLINE (>>=) #-}
   (>>=) (UnfoldM left) rightK =
     UnfoldM $ \ step init ->
     let
@@ -91,11 +92,13 @@
 foldable :: (Monad m, Foldable foldable) => foldable a -> UnfoldM m a
 foldable foldable = UnfoldM (\ step init -> A.foldlM step init foldable)
 
+{-| Filter -}
 {-# INLINE filter #-}
 filter :: Monad m => (a -> m Bool) -> UnfoldM m a -> UnfoldM m a
 filter test (UnfoldM run) = UnfoldM (\ step -> run (\ state element -> test element >>= bool (return state) (step state element)))
 
 {-| Ints in the specified inclusive range -}
+{-# INLINE intsInRange #-}
 intsInRange :: Monad m => Int -> Int -> UnfoldM m Int
 intsInRange from to =
   UnfoldM $ \ step init ->
@@ -107,3 +110,10 @@
           loop newState (succ int)
         else return state
     in loop init from
+
+{-| TVar contents -}
+{-# INLINE tVarValue #-}
+tVarValue :: TVar a -> UnfoldM STM a
+tVarValue var = UnfoldM $ \ step state -> do
+  a <- readTVar var
+  step state a