diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -53,3 +53,7 @@
 * Fourth version. Added new command line option variant "-r" and changed MMSyn7l.changeVolume function. Added for this purpose a new function 'adjustVolRes'.
 Added directory as an explicit dependency (earlier it has been implicit as a dependency for mmsyn7ukr package). Changed information in the README.markdown
 file appropriately.
+
+## 0.4.1.0 -- 2020-03-25
+
+* Fourth version revised A. Fixed issues with being not compiled for GHC 7.8.4 and for the wrong arguments specifying for 'adjustVolRes' function.
diff --git a/MMSyn7l.hs b/MMSyn7l.hs
--- a/MMSyn7l.hs
+++ b/MMSyn7l.hs
@@ -167,8 +167,8 @@
   dir <- listDirectory "."
   let dirV0 = L.sort . filter (L.isPrefixOf "result") $ dir
       dirV = V.fromList dirV0
-      first0 = concat . take 1 . drop 1 $ args
-      last0  = concat . take 1 . drop 2 $ args
+      first0 = concat . take 1 $ args
+      last0  = concat . take 1 . drop 1 $ args
       idxAllN = V.length dirV - 1
   onException (do { 
     let first1 = read first0::Int
@@ -177,7 +177,7 @@
         last2 = max (abs first1) (abs last1)
         first = if compare first2 idxAllN == GT then 0 else first2
         last =  if compare last2 idxAllN == GT then idxAllN else last2
-     ; mapM_ (changeVolume 1) (V.unsafeSlice first last dirV)
+     ; V.mapM_ (changeVolume 1) (V.unsafeSlice first last dirV)
      ; putStrLn ""
      ; putStrLn "Now you have changed (or left unchanged) the amplitudes for the needed \"result*.wav\" sound files." }) (do
          error "Please, specify a right numbers for the first and last files to be adjusted starting count from 0.")
diff --git a/mmsyn7l.cabal b/mmsyn7l.cabal
--- a/mmsyn7l.cabal
+++ b/mmsyn7l.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                mmsyn7l
-version:             0.4.0.0
+version:             0.4.1.0
 synopsis:            Modifies the amplitudes of the Ukrainian sounds representations created by mmsyn7ukr package.
 description:         A program and a library to modify the amplitudes of the Ukrainian sounds representations created by mmsyn7ukr package or somehow otherwise.
 homepage:            https://hackage.haskell.org/package/mmsyn7l