diff --git a/Data/List/Unique.hs b/Data/List/Unique.hs
--- a/Data/List/Unique.hs
+++ b/Data/List/Unique.hs
@@ -23,16 +23,11 @@
    where
 
 
-import Data.List
-   (
-     sort
-   , sortBy
-   , group
-   )
+import           Data.List           (group, sort, sortBy)
 
-import Data.List.Extra (nubOrd)
-import Data.Function (on)
-import Control.Applicative (liftA2)
+import           Control.Applicative (liftA2)
+import           Data.Function       (on)
+import           Data.List.Extra     (nubOrd)
 
 -- | 'sortUniq' sorts the list and removes the duplicates of elements. Example:
 --
@@ -84,7 +79,12 @@
 -- > count_ "foo bar" == [(' ',1),('a',1),('b',1),('f',1),('r',1),('o',2)]
 
 count_ :: Ord a => [a] -> [(a, Int)]
-count_ = sortBy (compare `on` snd) . map lh . sg
+count_ = sortBy (compare `on` snd) . count
+
+-- | 'occurrences' finds all elements of each occurrences.
+
+-- occurrences :: Ord a => [a] -> [(1,a)]
+-- occurrences =
 
 -- | 'countElem' gets the number of occurrences of the specified element. Example:
 --
diff --git a/Data/List/UniqueStrict.hs b/Data/List/UniqueStrict.hs
--- a/Data/List/UniqueStrict.hs
+++ b/Data/List/UniqueStrict.hs
@@ -21,22 +21,12 @@
         , count_ )
         where
 
-import qualified Data.Map.Strict as MS
-    (
-      Map
-    , fromListWith
-    , toList
-    , filter
-    , keys
-    )
+import qualified Data.Map.Strict    as MS (Map, filter, fromListWith, keys,
+                                           toList)
 
-import qualified Data.IntMap.Strict as IM
-    (
-      fromListWith
-    , toList
-    )
+import qualified Data.IntMap.Strict as IM (fromListWith, toList)
 
-import qualified Data.List as L (sort)
+import qualified Data.List          as L (sort)
 
 countMap :: Ord a => [a] -> MS.Map a Int
 countMap = MS.fromListWith (+) . flip zip (repeat 1)
diff --git a/Data/List/UniqueUnsorted.hs b/Data/List/UniqueUnsorted.hs
--- a/Data/List/UniqueUnsorted.hs
+++ b/Data/List/UniqueUnsorted.hs
@@ -23,21 +23,11 @@
         )
         where
 
-import Data.Hashable
-import qualified Data.HashMap.Strict as HS
-    (
-      HashMap
-    , fromListWith
-    , toList
-    , filter
-    , keys
-    )
+import           Data.Hashable
+import qualified Data.HashMap.Strict as HS (HashMap, filter, fromListWith, keys,
+                                            toList)
 
-import qualified Data.IntMap.Strict as IM
-    (
-      fromListWith
-    , toList
-    )
+import qualified Data.IntMap.Strict  as IM (fromListWith, toList)
 
 
 countMap :: (Hashable a, Eq a) => [a] -> HS.HashMap a Int
diff --git a/Unique.cabal b/Unique.cabal
--- a/Unique.cabal
+++ b/Unique.cabal
@@ -10,7 +10,7 @@
 -- PVP summary:      +-+------- breaking API changes
 --                   | | +----- non-breaking API additions
 --                   | | | +--- code changes with no API change
-version:             0.4.2
+version:             0.4.3
 
 -- A short (one-line) description of the package.
 synopsis:           It provides the functionality like unix "uniq" utility
@@ -59,7 +59,7 @@
   -- other-extensions:
 
   -- Other library packages from which modules are imported.
-  build-depends:         base >=4.0 && <= 4.8
+  build-depends:         base >=4.0 && < 5
                        , extra
                        , containers
                        , hashable
@@ -69,4 +69,4 @@
 
   -- Base language which the package is written in.
   default-language:    Haskell2010
-  ghc-options:         -O2 -Wall -fspec-constr-count=8 -funbox-strict-fields
+  ghc-options:         -Wall