diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,12 +1,21 @@
 Changelog
 =========
 
+Version 0.3.3.0
+---------------
+
+*December 3, 2019*
+
+<https://github.com/mstksg/nonempty-containers/releases/tag/v0.3.3.0>
+
+*   Add `overNonEmpty` and `onNonEmpty` in *Data.Containers.NonEmpty*.
+
 Version 0.3.1.0
 ---------------
 
 *October 21, 2019*
 
-<https://github.com/mstksg/nonempty-containers/releases/tag/v0.3.2.0>
+<https://github.com/mstksg/nonempty-containers/releases/tag/v0.3.3.0>
 
 *   Add `HasNonEmpty` instance for *nonempty-vector*
 *   Changed `splitLookup` to use `These` instead of a tuple of `Maybe`s.
diff --git a/nonempty-containers.cabal b/nonempty-containers.cabal
--- a/nonempty-containers.cabal
+++ b/nonempty-containers.cabal
@@ -4,10 +4,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: b3957939f119319cc87a4a5bed720ba0d54e8e7a4ddff1240df072483ee72097
+-- hash: 99b2f1d8a05c4c65da0f4e80d7fe63f0bba58499425adb66fc50f03895929c56
 
 name:           nonempty-containers
-version:        0.3.2.0
+version:        0.3.3.0
 synopsis:       Non-empty variants of containers data types, with full API
 description:    Efficient and optimized non-empty versions of types from /containers/.
                 Inspired by /non-empty-containers/ library, except attempting a more
diff --git a/src/Data/Containers/NonEmpty.hs b/src/Data/Containers/NonEmpty.hs
--- a/src/Data/Containers/NonEmpty.hs
+++ b/src/Data/Containers/NonEmpty.hs
@@ -24,6 +24,8 @@
 module Data.Containers.NonEmpty (
     HasNonEmpty(..)
   , pattern IsNonEmpty, pattern IsEmpty
+  , overNonEmpty
+  , onNonEmpty
   ) where
 
 import           Data.IntMap            (IntMap)
@@ -107,6 +109,23 @@
     unsafeToNonEmpty = fromMaybe e . nonEmpty
       where
         e = errorWithoutStackTrace "unsafeToNonEmpty: empty input provided"
+
+-- | Useful function for mapping over the "non-empty" representation of
+-- a type.
+--
+-- @since 0.3.3.0
+overNonEmpty :: (HasNonEmpty s, HasNonEmpty t) => (NE s -> NE t) -> s -> t
+overNonEmpty f = withNonEmpty empty (fromNonEmpty . f)
+
+-- | Useful function for applying a function on the "non-empty"
+-- representation of a type.
+--
+-- If you want a continuation taking @'NE' s -> 'Maybe r'@, you can
+-- use @'withNonEmpty' 'Nothing'@.
+--
+-- @since 0.3.3.0
+onNonEmpty :: HasNonEmpty s => (NE s -> r) -> s -> Maybe r
+onNonEmpty f = withNonEmpty Nothing (Just . f)
 
 instance HasNonEmpty [a] where
     type NE [a] = NonEmpty a