diff --git a/.hlint.ignore b/.hlint.ignore
index 918028b13..ef696f0bc 100644
--- a/.hlint.ignore
+++ b/.hlint.ignore
@@ -14,7 +14,7 @@ src/Streamly/Internal/Data/Stream/StreamD.hs
 src/Streamly/Internal/Data/Pipe/Types.hs
 src/Streamly/Internal/Data/SmallArray/Types.hs
 src/Streamly/Internal/Data/Unicode/Stream.hs
-src/Streamly/Internal/Mutable/Prim/Var.hs
+src/Streamly/Internal/Data/IORef/Prim.hs
 src/Streamly/Internal/Data/Array/Prim/Types.hs
 src/Streamly/Internal/Data/Array/Prim/MutTypesInclude.hs
 src/Streamly/Internal/Data/Array/Prim/TypesInclude.hs
diff --git a/src/Streamly/Internal/Data/IORef/Prim.hs b/src/Streamly/Internal/Data/IORef/Prim.hs
new file mode 100644
index 000000000..6a4a1f311
--- /dev/null
+++ b/src/Streamly/Internal/Data/IORef/Prim.hs
@@ -0,0 +1,84 @@
+{-# LANGUAGE UnboxedTuples #-}
+
+#include "inline.hs"
+
+-- |
+-- Module      : Streamly.Internal.Data.IORef.Prim
+-- Copyright   : (c) 2019 Composewell Technologies
+--
+-- License     : BSD3
+-- Maintainer  : streamly@composewell.com
+-- Stability   : experimental
+-- Portability : GHC
+--
+-- A mutable variable in a mutation capable monad (IO) holding a 'Prim'
+-- value. This allows fast modification because of unboxed storage.
+--
+-- = Multithread Consistency Notes
+--
+-- In general, any value that straddles a machine word cannot be guaranteed to
+-- be consistently read from another thread without a lock.  GHC heap objects
+-- are always machine word aligned, therefore, a 'IORef' is also word aligned.
+-- On a 64-bit platform, writing a 64-bit aligned type from one thread and
+-- reading it from another thread should give consistent old or new value. The
+-- same holds true for 32-bit values on a 32-bit platform.
+
+module Streamly.Internal.Data.IORef.Prim
+    (
+      IORef
+    , Prim
+
+    -- * Construction
+    , newIORef
+
+    -- * Write
+    , writeIORef
+    , modifyIORef'
+
+    -- * Read
+    , readIORef
+    )
+where
+
+import Control.Monad.Primitive (primitive_)
+import Data.Primitive.Types (Prim, sizeOf#, readByteArray#, writeByteArray#)
+import GHC.Exts (MutableByteArray#, newByteArray#, RealWorld)
+import GHC.IO (IO(..))
+
+-- | An 'IORef' holds a single 'Prim' value.
+data IORef a = IORef (MutableByteArray# RealWorld)
+
+-- | Create a new 'IORef'.
+--
+-- /Internal/
+{-# INLINE newIORef #-}
+newIORef :: forall a. Prim a => a -> IO (IORef a)
+newIORef x = IO (\s# ->
+      case newByteArray# (sizeOf# (undefined :: a)) s# of
+        (# s1#, arr# #) ->
+            case writeByteArray# arr# 0# x s1# of
+                s2# -> (# s2#, IORef arr# #)
+    )
+
+-- | Write a value to an 'IORef'.
+--
+-- /Internal/
+{-# INLINE writeIORef #-}
+writeIORef :: Prim a => IORef a -> a -> IO ()
+writeIORef (IORef arr#) x = primitive_ (writeByteArray# arr# 0# x)
+
+-- | Read a value from an 'IORef'.
+--
+-- /Internal/
+{-# INLINE readIORef #-}
+readIORef :: Prim a => IORef a -> IO a
+readIORef (IORef arr#) = IO (readByteArray# arr# 0#)
+
+-- | Modify the value of an 'IORef' using a function with strict application.
+--
+-- /Internal/
+{-# INLINE modifyIORef' #-}
+modifyIORef' :: Prim a => IORef a -> (a -> a) -> IO ()
+modifyIORef' (IORef arr#) g = primitive_ $ \s# ->
+  case readByteArray# arr# 0# s# of
+    (# s'#, a #) -> let a' = g a in a' `seq` writeByteArray# arr# 0# a' s'#
diff --git a/src/Streamly/Internal/Data/Stream/IsStream.hs b/src/Streamly/Internal/Data/Stream/IsStream.hs
index 7785f5829..3c68112e3 100644
--- a/src/Streamly/Internal/Data/Stream/IsStream.hs
+++ b/src/Streamly/Internal/Data/Stream/IsStream.hs
@@ -66,7 +66,7 @@ module Streamly.Internal.Data.Stream.IsStream
     , fromListM
     , K.fromFoldable
     , fromFoldableM
-    , fromPrimVar
+    , fromPrimIORef
     , fromCallback
 
     -- * Elimination
@@ -553,7 +553,7 @@ import Streamly.Internal.Data.Pipe.Types (Pipe (..))
 import Streamly.Internal.Data.Time.Units
        ( AbsTime, MilliSecond64(..), addToAbsTime, toRelTime
        , toAbsTime, TimeUnit64, RelTime64, addToAbsTime64)
-import Streamly.Internal.Mutable.Prim.Var (Prim, Var)
+import Streamly.Internal.Data.IORef.Prim (Prim, IORef)
 import Streamly.Internal.Data.Tuple.Strict (Tuple'(..))
 
 import qualified Streamly.Internal.Memory.Array as A
@@ -978,13 +978,13 @@ fromHandle h = go
             str <- liftIO $ IO.hGetLine h
             yld str go
 
--- | Construct a stream by reading a 'Prim' 'Var' repeatedly.
+-- | Construct a stream by reading a 'Prim' 'IORef' repeatedly.
 --
 -- /Internal/
 --
-{-# INLINE fromPrimVar #-}
-fromPrimVar :: (IsStream t, MonadIO m, Prim a) => Var IO a -> t m a
-fromPrimVar = fromStreamD . D.fromPrimVar
+{-# INLINE fromPrimIORef #-}
+fromPrimIORef :: (IsStream t, MonadIO m, Prim a) => IORef a -> t m a
+fromPrimIORef = fromStreamD . D.fromPrimIORef
 
 -- | Takes a callback setter function and provides it with a callback.  The
 -- callback when invoked adds a value at the tail of the stream. Returns a
diff --git a/src/Streamly/Internal/Data/Stream/StreamD.hs b/src/Streamly/Internal/Data/Stream/StreamD.hs
index 6495f1307..fae39618c 100644
--- a/src/Streamly/Internal/Data/Stream/StreamD.hs
+++ b/src/Streamly/Internal/Data/Stream/StreamD.hs
@@ -81,7 +81,7 @@ module Streamly.Internal.Data.Stream.StreamD
     , fromListM
     , fromStreamK
     , fromStreamD
-    , fromPrimVar
+    , fromPrimIORef
     , fromSVar
 
     -- * Elimination
@@ -325,8 +325,7 @@ import Foreign.Storable (Storable(..))
 import GHC.Types (SPEC(..))
 import System.Mem (performMajorGC)
 import Fusion.Plugin.Types (Fuse(..))
-import Streamly.Internal.Mutable.Prim.Var
-       (Prim, Var, readVar, newVar, modifyVar')
+import Streamly.Internal.Data.IORef.Prim (Prim)
 import Streamly.Internal.Data.Time.Units
        (TimeUnit64, toRelTime64, diffAbsTime64, RelTime64)
 import Streamly.Internal.Data.Atomics (atomicModifyIORefCAS_)
@@ -341,6 +340,7 @@ import Streamly.Internal.Data.Unfold.Types (Unfold(..))
 import Streamly.Internal.Data.Tuple.Strict (Tuple3'(..))
 import Streamly.Internal.Data.Stream.SVar (fromConsumer, pushToFold)
 
+import qualified Streamly.Internal.Data.IORef.Prim as Prim
 import qualified Streamly.Internal.Data.Pipe.Types as Pipe
 import qualified Streamly.Internal.Memory.Array.Types as A
 import qualified Streamly.Internal.Memory.Mutable.Array.Types as MA
@@ -677,12 +677,12 @@ fromListM = Stream step
 toStreamD :: (K.IsStream t, Monad m) => t m a -> Stream m a
 toStreamD = fromStreamK . K.toStream
 
-{-# INLINE_NORMAL fromPrimVar #-}
-fromPrimVar :: (MonadIO m, Prim a) => Var IO a -> Stream m a
-fromPrimVar var = Stream step ()
+{-# INLINE_NORMAL fromPrimIORef #-}
+fromPrimIORef :: (MonadIO m, Prim a) => Prim.IORef a -> Stream m a
+fromPrimIORef var = Stream step ()
   where
     {-# INLINE_LATE step #-}
-    step _ () = liftIO (readVar var) >>= \x -> return $ Yield x ()
+    step _ () = liftIO (Prim.readIORef var) >>= \x -> return $ Yield x ()
 
 -------------------------------------------------------------------------------
 -- Generation from SVar
@@ -3811,17 +3811,17 @@ pollCounts predicate transf fld (Stream step state) = Stream step' Nothing
         -- As long as we are using an "Int" for counts lockfree reads from
         -- Var should work correctly on both 32-bit and 64-bit machines.
         -- However, an Int on a 32-bit machine may overflow quickly.
-        countVar <- liftIO $ newVar (0 :: Int)
+        countVar <- liftIO $ Prim.newIORef (0 :: Int)
         tid <- forkManaged
             $ void $ runFold fld
-            $ transf $ fromPrimVar countVar
+            $ transf $ fromPrimIORef countVar
         return $ Skip (Just (countVar, tid, state))
 
     step' gst (Just (countVar, tid, st)) = do
         r <- step gst st
         case r of
             Yield x s -> do
-                when (predicate x) $ liftIO $ modifyVar' countVar (+ 1)
+                when (predicate x) $ liftIO $ Prim.modifyIORef' countVar (+ 1)
                 return $ Yield x (Just (countVar, tid, s))
             Skip s -> return $ Skip (Just (countVar, tid, s))
             Stop -> do
@@ -3842,12 +3842,12 @@ tapRate samplingRate action (Stream step state) = Stream step' Nothing
         i <-
             MC.catch
                 (do liftIO $ threadDelay (round $ samplingRate * 1000000)
-                    i <- liftIO $ readVar countVar
+                    i <- liftIO $ Prim.readIORef countVar
                     let !diff = i - prev
                     void $ action diff
                     return i)
                 (\(e :: AsyncException) -> do
-                     i <- liftIO $ readVar countVar
+                     i <- liftIO $ Prim.readIORef countVar
                      let !diff = i - prev
                      void $ action diff
                      throwM (MC.toException e))
@@ -3855,7 +3855,7 @@ tapRate samplingRate action (Stream step state) = Stream step' Nothing
 
     {-# INLINE_LATE step' #-}
     step' _ Nothing = do
-        countVar <- liftIO $ newVar 0
+        countVar <- liftIO $ Prim.newIORef 0
         tid <- fork $ loop countVar 0
         ref <- liftIO $ newIORef ()
         _ <- liftIO $ mkWeakIORef ref (killThread tid)
@@ -3865,7 +3865,7 @@ tapRate samplingRate action (Stream step state) = Stream step' Nothing
         r <- step gst st
         case r of
             Yield x s -> do
-                liftIO $ modifyVar' countVar (+ 1)
+                liftIO $ Prim.modifyIORef' countVar (+ 1)
                 return $ Yield x (Just (countVar, tid, s, ref))
             Skip s -> return $ Skip (Just (countVar, tid, s, ref))
             Stop -> do
@@ -4628,13 +4628,13 @@ dropByTime duration (Stream step1 state1) = Stream step (DropByTimeInit state1)
              Stop -> Stop
 
 {-# INLINE updateTimeVar #-}
-updateTimeVar :: Var IO Int64 -> IO ()
+updateTimeVar :: Prim.IORef Int64 -> IO ()
 updateTimeVar timeVar = do
     MicroSecond64 t <- fromAbsTime <$> getTime Monotonic
-    modifyVar' timeVar (const t)
+    Prim.modifyIORef' timeVar (const t)
 
 {-# INLINE updateWithDelay #-}
-updateWithDelay :: RealFrac a => a -> Var IO Int64 -> IO ()
+updateWithDelay :: RealFrac a => a -> Prim.IORef Int64 -> IO ()
 updateWithDelay precision timeVar = do
     threadDelay (delayTime precision)
     updateTimeVar timeVar
@@ -4666,14 +4666,14 @@ times g = Stream step Nothing
         -- XXX note that this is safe only on a 64-bit machine. On a 32-bit
         -- machine a 64-bit 'Var' cannot be read consistently without a lock
         -- while another thread is writing to it.
-        timeVar <- liftIO $ newVar (0 :: Int64)
+        timeVar <- liftIO $ Prim.newIORef (0 :: Int64)
         liftIO $ updateTimeVar timeVar
         tid <- forkManaged $ liftIO $ forever (updateWithDelay g timeVar)
-        a <- liftIO $ readVar timeVar
+        a <- liftIO $ Prim.readIORef timeVar
         return $ Skip $ Just (timeVar, tid, a)
 
     step _ s@(Just (timeVar, _, t0)) = do
-        a <- liftIO $ readVar timeVar
+        a <- liftIO $ Prim.readIORef timeVar
         -- XXX we can perhaps use an AbsTime64 using a 64 bit Int for
         -- efficiency.  or maybe we can use a representation using Double for
         -- floating precision time
diff --git a/src/Streamly/Internal/Mutable/Prim/Var.hs b/src/Streamly/Internal/Mutable/Prim/Var.hs
deleted file mode 100644
index 77771ce94..000000000
--- a/src/Streamly/Internal/Mutable/Prim/Var.hs
+++ /dev/null
@@ -1,83 +0,0 @@
-{-# LANGUAGE UnboxedTuples #-}
-
-#include "inline.hs"
-
--- |
--- Module      : Streamly.Internal.Mutable.Prim.Var
--- Copyright   : (c) 2019 Composewell Technologies
---
--- License     : BSD3
--- Maintainer  : streamly@composewell.com
--- Stability   : experimental
--- Portability : GHC
---
--- A mutable variable in a mutation capable monad (IO/ST) holding a 'Prim'
--- value. This allows fast modification because of unboxed storage.
---
--- = Multithread Consistency Notes
---
--- In general, any value that straddles a machine word cannot be guaranteed to
--- be consistently read from another thread without a lock.  GHC heap objects
--- are always machine word aligned, therefore, a 'Var' is also word aligned. On
--- a 64-bit platform, writing a 64-bit aligned type from one thread and reading
--- it from another thread should give consistent old or new value. The same
--- holds true for 32-bit values on a 32-bit platform.
-
-module Streamly.Internal.Mutable.Prim.Var
-    (
-      Var
-    , MonadMut
-    , Prim
-
-    -- * Construction
-    , newVar
-
-    -- * Write
-    , writeVar
-    , modifyVar'
-
-    -- * Read
-    , readVar
-    )
-where
-
-import Control.Monad.Primitive (PrimMonad(..), primitive_)
-import Data.Primitive.Types (Prim, sizeOf#, readByteArray#, writeByteArray#)
-import GHC.Exts (MutableByteArray#, newByteArray#)
-
--- | A 'Var' holds a single 'Prim' value.
-data Var m a = Var (MutableByteArray# (PrimState m))
-
--- The name PrimMonad does not give a clue what it means, an explicit "Mut"
--- suffix provides a better hint. MonadMut is just a generalization of MonadIO.
---
--- | A monad that allows mutable operations using a state token.
-type MonadMut = PrimMonad
-
--- | Create a new mutable variable.
-{-# INLINE newVar #-}
-newVar :: forall m a. (MonadMut m, Prim a) => a -> m (Var m a)
-newVar x = primitive (\s# ->
-      case newByteArray# (sizeOf# (undefined :: a)) s# of
-        (# s1#, arr# #) ->
-            case writeByteArray# arr# 0# x s1# of
-                s2# -> (# s2#, Var arr# #)
-    )
-
--- | Write a value to a mutable variable.
-{-# INLINE writeVar #-}
-writeVar :: (MonadMut m, Prim a) => Var m a -> a -> m ()
-writeVar (Var arr#) x = primitive_ (writeByteArray# arr# 0# x)
-
--- | Read a value from a variable.
-{-# INLINE readVar #-}
-readVar :: (MonadMut m, Prim a) => Var m a -> m a
-readVar (Var arr#) = primitive (readByteArray# arr# 0#)
-
--- | Modify the value of a mutable variable using a function with strict
--- application.
-{-# INLINE modifyVar' #-}
-modifyVar' :: (MonadMut m, Prim a) => Var m a -> (a -> a) -> m ()
-modifyVar' (Var arr#) g = primitive_ $ \s# ->
-  case readByteArray# arr# 0# s# of
-    (# s'#, a #) -> let a' = g a in a' `seq` writeByteArray# arr# 0# a' s'#
diff --git a/streamly.cabal b/streamly.cabal
index ba61a4dd1..ead7edf7c 100644
--- a/streamly.cabal
+++ b/streamly.cabal
@@ -386,7 +386,7 @@ library
                      , Streamly.Internal.Data.SVar
 
                      -- Mutable data
-                     , Streamly.Internal.Mutable.Prim.Var
+                     , Streamly.Internal.Data.IORef.Prim
 
                      -- Arrays
                      , Streamly.Internal.Data.Array