diff --git a/cases.cabal b/cases.cabal
--- a/cases.cabal
+++ b/cases.cabal
@@ -1,28 +1,26 @@
 cabal-version: 3.0
-name:          cases
-version:       0.1.4.3
-synopsis:      A converter for spinal, snake and camel cases
+name: cases
+version: 0.1.4.4
+synopsis: A converter for spinal, snake and camel cases
 description:
   A parser-based converter library for spinal, snake and camel cases.
 
-category:      Text
-homepage:      https://github.com/nikita-volkov/cases 
-bug-reports:   https://github.com/nikita-volkov/cases/issues 
-author:        Nikita Volkov <nikita.y.volkov@mail.ru>
-maintainer:    Nikita Volkov <nikita.y.volkov@mail.ru>
-copyright:     (c) 2014, Nikita Volkov
-license:       MIT
-license-file:  LICENSE
+category: Text
+homepage: https://github.com/nikita-volkov/cases
+bug-reports: https://github.com/nikita-volkov/cases/issues
+author: Nikita Volkov <nikita.y.volkov@mail.ru>
+maintainer: Nikita Volkov <nikita.y.volkov@mail.ru>
+copyright: (c) 2014, Nikita Volkov
+license: MIT
+license-file: LICENSE
 
 source-repository head
-  type:     git
-  location: git://github.com/nikita-volkov/cases.git
+  type: git
+  location: https://github.com/nikita-volkov/cases
 
 common base
-  default-language:   Haskell2010
+  default-language: Haskell2010
   default-extensions:
-    NoImplicitPrelude
-    NoMonomorphismRestriction
     Arrows
     BangPatterns
     BlockArguments
@@ -41,11 +39,12 @@
     GADTs
     GeneralizedNewtypeDeriving
     LambdaCase
-    LambdaCase
     LiberalTypeSynonyms
     MagicHash
     MultiParamTypeClasses
     MultiWayIf
+    NoImplicitPrelude
+    NoMonomorphismRestriction
     OverloadedStrings
     ParallelListComp
     PatternGuards
@@ -61,33 +60,40 @@
     UnboxedTuples
 
 library
-  import:          base
-  hs-source-dirs:  library
+  import: base
+  hs-source-dirs: library
   exposed-modules: Cases
-  other-modules:   Cases.Prelude
+  other-modules: Cases.Prelude
   build-depends:
-    , attoparsec >=0.13 && <0.15
-    , base >=4.11 && <5
-    , text >=1 && <3
+    attoparsec >=0.13 && <0.15,
+    base >=4.11 && <5,
+    text >=1 && <3,
 
 test-suite api-tests
-  import:         base
-  type:           exitcode-stdio-1.0
+  import: base
+  type: exitcode-stdio-1.0
   hs-source-dirs: api-tests
-  main-is:        Main.hs
-  ghc-options:    -threaded -with-rtsopts=-N
+  main-is: Main.hs
+  ghc-options:
+    -threaded
+    -with-rtsopts=-N
+
   build-depends:
-    , cases
-    , hspec >=2.11 && <3
-    , rerebase >=1 && <2
+    cases,
+    hspec >=2.11 && <3,
+    rerebase >=1 && <2,
 
 benchmark benchmark
-  import:         base
-  type:           exitcode-stdio-1.0
+  import: base
+  type: exitcode-stdio-1.0
   hs-source-dirs: benchmark
-  main-is:        Benchmark.hs
-  ghc-options:    -O2 -threaded -with-rtsopts=-N
+  main-is: Benchmark.hs
+  ghc-options:
+    -O2
+    -threaded
+    -with-rtsopts=-N
+
   build-depends:
-    , cases
-    , criterion >=1.6.3 && <2
-    , rerebase >=1 && <2
+    cases,
+    criterion >=1.6.3 && <2,
+    rerebase >=1 && <2,
diff --git a/library/Cases.hs b/library/Cases.hs
--- a/library/Cases.hs
+++ b/library/Cases.hs
@@ -81,30 +81,38 @@
 
 type Folder r = r -> Part -> r
 
-type Delimiter = Folder (Maybe T.Text)
+newtype Delimiter = Delimiter (Maybe T.Text -> Part -> Maybe T.Text)
 
 spinal :: Delimiter
 spinal =
-  (. partToText)
-    . fmap Just
-    . maybe id (\l r -> l <> "-" <> r)
+  Delimiter
+    ( (. partToText)
+        . fmap Just
+        . maybe id (\l r -> l <> "-" <> r)
+    )
 
 snake :: Delimiter
 snake =
-  (. partToText)
-    . fmap Just
-    . maybe id (\l r -> l <> "_" <> r)
+  Delimiter
+    ( (. partToText)
+        . fmap Just
+        . maybe id (\l r -> l <> "_" <> r)
+    )
 
 whitespace :: Delimiter
 whitespace =
-  (. partToText)
-    . fmap Just
-    . maybe id (\l r -> l <> " " <> r)
+  Delimiter
+    ( (. partToText)
+        . fmap Just
+        . maybe id (\l r -> l <> " " <> r)
+    )
 
 camel :: Delimiter
 camel =
-  fmap Just
-    . maybe partToText (\l r -> l <> partToText (title r))
+  Delimiter
+    ( fmap Just
+        . maybe partToText (\l r -> l <> partToText (title r))
+    )
 
 -- * CaseTransformers
 
@@ -160,7 +168,7 @@
 --
 -- Note: to skip case transformation use the 'id' function.
 process :: CaseTransformer -> Delimiter -> T.Text -> T.Text
-process tr fo =
+process tr (Delimiter fo) =
   fromMaybe ""
     . either (error . ("Parse failure: " <>)) id
     . A.parseOnly (partsParser $ (. tr) . fo)