diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,11 @@
+# Version 1.2.1.1
+  - Dependency bump for time 1.6.
+
+# Version 1.2.1.0
+  - Added `System.IO.Streams.mapMaybe` for InputStream.
+
+  - Added `System.IO.Streams.contramapMaybe` for OutputStream.
+
 # Version 1.2.0.1
 
   - `System.IO.Streams.Attoparsec.parseFromStream`: export more information
diff --git a/io-streams.cabal b/io-streams.cabal
--- a/io-streams.cabal
+++ b/io-streams.cabal
@@ -1,5 +1,5 @@
 Name:                io-streams
-Version:             1.2.0.1
+Version:             1.2.1.1
 License:             BSD3
 License-file:        LICENSE
 Category:            Data, Network, IO-Streams
@@ -126,7 +126,7 @@
                      primitive     >= 0.2   && <0.6,
                      process       >= 1     && <1.3,
                      text          >= 0.10  && <1.3,
-                     time          >= 1.2   && <1.5,
+                     time          >= 1.2   && <1.6,
                      transformers  >= 0.2   && <0.5,
                      vector        >= 0.7   && <0.11,
                      zlib-bindings >= 0.1   && <0.2
@@ -138,6 +138,7 @@
     BangPatterns,
     CPP,
     DeriveDataTypeable,
+    FlexibleContexts,
     FlexibleInstances,
     GeneralizedNewtypeDeriving,
     MultiParamTypeClasses,
@@ -211,7 +212,7 @@
                      primitive     >= 0.2   && <0.6,
                      process       >= 1     && <1.3,
                      text          >= 0.10  && <1.3,
-                     time          >= 1.2   && <1.5,
+                     time          >= 1.2   && <1.6,
                      transformers  >= 0.2   && <0.5,
                      vector        >= 0.7   && <0.11,
                      zlib-bindings >= 0.1   && <0.2,
diff --git a/src/System/IO/Streams/Combinators.hs b/src/System/IO/Streams/Combinators.hs
--- a/src/System/IO/Streams/Combinators.hs
+++ b/src/System/IO/Streams/Combinators.hs
@@ -22,9 +22,11 @@
  , map
  , mapM
  , mapM_
+ , mapMaybe
  , contramap
  , contramapM
  , contramapM_
+ , contramapMaybe
 
    -- * Filter
  , filter
@@ -370,6 +372,33 @@
 
 
 ------------------------------------------------------------------------------
+-- | A version of map that discards elements
+--
+-- @mapMaybe f s@ passes all output from @s@ through the function @f@ and
+-- discards elements for which @f s@ evaluates to 'Nothing'.
+--
+-- Example:
+--
+-- @
+-- ghci> Streams.'System.IO.Streams.fromList' [Just 1, None, Just 3] >>=
+--       Streams.'mapMaybe' 'id' >>=
+--       Streams.'System.IO.Streams.toList'
+-- [1,3]
+-- @
+--
+-- /Since: 1.2.1.0/
+mapMaybe :: (a -> Maybe b) -> InputStream a -> IO (InputStream b)
+mapMaybe f src = makeInputStream g
+  where
+    g = do
+      s <- read src
+      case s of
+        Nothing -> return Nothing
+        Just x ->
+          case f x of
+            Nothing -> g
+            y -> return y
+------------------------------------------------------------------------------
 -- | Contravariant counterpart to 'map'.
 --
 -- @contramap f s@ passes all input to @s@ through the function @f@.
@@ -415,6 +444,24 @@
 contramapM_ f s = makeOutputStream $ \mb -> do
     _ <- maybe (return $! ()) (void . f) mb
     write mb s
+
+
+------------------------------------------------------------------------------
+-- | Contravariant counterpart to 'contramapMaybe'.
+--
+-- @contramap f s@ passes all input to @s@ through the function @f@.
+-- Discards all the elements for which @f@ returns 'Nothing'.
+--
+-- /Since: 1.2.1.0/
+--
+contramapMaybe :: (a -> Maybe b) -> OutputStream b -> IO (OutputStream a)
+contramapMaybe f s = makeOutputStream $ g
+    where
+      g Nothing = write Nothing s
+      g (Just a) =
+        case f a of
+          Nothing -> return ()
+          x -> write x s
 
 
 ------------------------------------------------------------------------------
diff --git a/src/System/IO/Streams/Internal/Attoparsec.hs b/src/System/IO/Streams/Internal/Attoparsec.hs
--- a/src/System/IO/Streams/Internal/Attoparsec.hs
+++ b/src/System/IO/Streams/Internal/Attoparsec.hs
@@ -3,6 +3,7 @@
 
 {-# LANGUAGE BangPatterns       #-}
 {-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE FlexibleContexts   #-}
 {-# LANGUAGE OverloadedStrings  #-}
 
 module System.IO.Streams.Internal.Attoparsec
diff --git a/test/System/IO/Streams/Tests/Combinators.hs b/test/System/IO/Streams/Tests/Combinators.hs
--- a/test/System/IO/Streams/Tests/Combinators.hs
+++ b/test/System/IO/Streams/Tests/Combinators.hs
@@ -46,7 +46,9 @@
         , testContramap
         , testMapM
         , testMapM_
+        , testMapMaybe
         , testContramapM_
+        , testContramapMaybe
         , testSkipToEof
         , testZip
         , testZipWith
@@ -128,6 +130,15 @@
 
 
 ------------------------------------------------------------------------------
+testMapMaybe :: Test
+testMapMaybe = testCase "combinators/mapMaybe" $ do
+    is <- fromList [1,2,3::Int] >>= S.mapMaybe (\x -> if odd x then Just (x * x) else Nothing)
+    l  <- toList is
+
+    assertEqual "mapMaybe" [1,9] l
+
+
+------------------------------------------------------------------------------
 testContramapM_ :: Test
 testContramapM_ = testCase "combinators/contramapM_" $ do
     ref <- newIORef 0
@@ -135,6 +146,15 @@
     _   <- outputToList (contramapM_ (modifyIORef ref . (+)) >=> connect is)
 
     readIORef ref >>= assertEqual "contramapM_" 6
+
+
+------------------------------------------------------------------------------
+testContramapMaybe :: Test
+testContramapMaybe = testCase "combinators/contramapMaybe" $ do
+    is  <- fromList [1,2,3::Int]
+    l   <- outputToList (contramapMaybe f >=> connect is)
+    assertEqual "contramapMaybe" [1,9] l
+    where f x = if even x then Nothing else Just $ x * x
 
 
 ------------------------------------------------------------------------------