diff --git a/hw-streams.cabal b/hw-streams.cabal
--- a/hw-streams.cabal
+++ b/hw-streams.cabal
@@ -3,7 +3,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           hw-streams
-version:        0.0.0.1
+version:        0.0.0.2
 synopsis:       Primitive functions and data types
 description:    Primitive functions and data types.
 category:       Data
diff --git a/src/HaskellWorks/Data/Streams/Stream.hs b/src/HaskellWorks/Data/Streams/Stream.hs
--- a/src/HaskellWorks/Data/Streams/Stream.hs
+++ b/src/HaskellWorks/Data/Streams/Stream.hs
@@ -101,3 +101,12 @@
 repeat :: Int -> a -> Stream a
 repeat n a = Stream step n 1
   where step i = if i > 0 then Yield a (i - 1) else Done
+
+transcribe :: (s -> a -> b) -> s -> Stream a -> Stream b
+transcribe f w (Stream step state size) = Stream step' (state, w) size
+  where step' (t, x) = case step t of
+          Yield a s' -> let z = f x a in Yield z (s', x)
+          Skip    s' -> Skip (s', x)
+          Done       -> Done
+        {-# INLINE step' #-}
+{-# INLINE transcribe #-}