diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -8,3 +8,7 @@
 
 * Second version. Added some optimizations for the Data.Phonetic.Languages.Base module functions. Added new functions to
 the module.
+
+## 0.2.1.0 -- 2021-04-20
+
+* Second version revised A. Fixed issues with being not compiled for GHC versions less than 8.2. 
diff --git a/Data/Phonetic/Languages/Base.hs b/Data/Phonetic/Languages/Base.hs
--- a/Data/Phonetic/Languages/Base.hs
+++ b/Data/Phonetic/Languages/Base.hs
@@ -1,6 +1,7 @@
 {-# OPTIONS_HADDOCK show-extensions #-}
 {-# OPTIONS_GHC -funbox-strict-fields #-}
 {-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE UnboxedTuples #-}
 {-# LANGUAGE MagicHash #-}
 
@@ -234,10 +235,24 @@
   -> Array Int PhoneticsRepresentationPLX
   -> Maybe PhoneticsRepresentationPLX
 findSA repr arr = gBF3 (# i#, k #) (# j#, m #) repr arr 
-     where (!(I# i#),!(I# j#)) = bounds arr
+     where !(I# i#,I# j#) = bounds arr
            !k = unsafeAt arr (I# i#)
            !m = unsafeAt arr (I# i#)
 
+{-| The following is taken from the 'Data.Either' module from @base@ package.
+-}
+#ifdef __GLASGOW_HASKELL__
+#if __GLASGOW_HASKELL__<802
+fromLeft :: a -> Either a b -> a
+fromLeft _ (Left x) = x
+fromLeft def _ = def
+
+fromRight :: b -> Either a b -> b
+fromRight _ (Right x) = x
+fromRight def _ = def
+#endif
+#endif
+
 findSAI
   :: PhoneticRepresentationXInter
   -> (String, String)
@@ -246,7 +261,7 @@
 findSAI repr (xs,ys) arr
  | isLeft repr = gBF3 (# i#, k #) (# j#, m #) (fromX2PRPL . fromLeft (PREmptyC " " ' ') $ repr) arr
  | otherwise = gBF3 (# i#, k #) (# j#, m #) (str2PRPL (fromRight [] repr) (xs,ys)) arr
-     where (!(I# i#),!(I# j#)) = bounds arr
+     where !(I# i#,I# j#) = bounds arr
            !k = unsafeAt arr (I# i#)
            !m = unsafeAt arr (I# i#)
            str2PRPL :: String -> (String,String) -> PhoneticsRepresentationPL
diff --git a/Data/Phonetic/Languages/Undefined.hs b/Data/Phonetic/Languages/Undefined.hs
--- a/Data/Phonetic/Languages/Undefined.hs
+++ b/Data/Phonetic/Languages/Undefined.hs
@@ -11,7 +11,7 @@
 -- The functions themselves are 'undefined' but with some type. They are just templates and some general idea.
 -- Please, provide your own implementation instead of using these ones.
 
-module Data.Phonetic.Languages.Undefined {-# WARNING "This module contains just some templates and ideas. Please, provide the analogous functions by yourself, these ones while used returns 'undefined'. " #-} (
+module Data.Phonetic.Languages.Undefined {-# WARNING "This module contains just some templates and ideas. Please, provide the analogous functions by yourself, these ones while used return 'undefined'. " #-} (
   -- * Convert to the 'PhoneticsRepresentationPL'.
   stringToPRPL
   -- * Apply conversion from 'PhoneticsRepresentationPL'.
diff --git a/phonetic-languages-phonetics-basics.cabal b/phonetic-languages-phonetics-basics.cabal
--- a/phonetic-languages-phonetics-basics.cabal
+++ b/phonetic-languages-phonetics-basics.cabal
@@ -3,7 +3,7 @@
 -- http://haskell.org/cabal/users-guide/
 
 name:                phonetic-languages-phonetics-basics
-version:             0.2.0.0
+version:             0.2.1.0
 synopsis:            A library for working with generalized phonetic languages usage.
 description:         There already exists a Ukrainian implementation for the phonetic languages approach published at: https://hackage.haskell.org/package/phonetic-languages-simplified-examples-array. It is optimized for the Ukrainian only and needs to be rewritten for every new language mostly from scratch using it as a template. To avoid this boilerplate, this one is provided. It can be used for different languages and even for music or other fields. 
 homepage:            https://hackage.haskell.org/package/phonetic-languages-phonetics-basics
@@ -20,7 +20,7 @@
 library
   exposed-modules:     Data.Phonetic.Languages.Undefined, Data.Phonetic.Languages.Base
   -- other-modules:
-  other-extensions:    BangPatterns, UnboxedTuples, MagicHash
+  other-extensions:    CPP, BangPatterns, UnboxedTuples, MagicHash
   ghc-options:         -funbox-strict-fields
   build-depends:       base >=4.8 && <4.15
   -- hs-source-dirs: