diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -78,3 +78,7 @@
 ## 0.13.0.0 -- 2020-08-16
 
 * Thirteenth version. Fixed issues with being not compiled. 
+
+## 0.13.0.0 -- 2020-08-16
+
+* Fourteenth version. Fixed issues with being not compiled. 
diff --git a/DobutokO/Poetry/UniquenessPeriodsG.hs b/DobutokO/Poetry/UniquenessPeriodsG.hs
--- a/DobutokO/Poetry/UniquenessPeriodsG.hs
+++ b/DobutokO/Poetry/UniquenessPeriodsG.hs
@@ -14,8 +14,8 @@
 module DobutokO.Poetry.UniquenessPeriodsG where
 
 #ifdef __GLASGOW_HASKELL__
-#if __GLASGOW_HASKELL__>=804
-/* code that applies only to GHC 8.4.* and higher versions */
+#if __GLASGOW_HASKELL__>=710
+/* code that applies only to GHC 7.10.* and higher versions */
 import GHC.Base (mconcat)
 #endif
 #endif
@@ -25,8 +25,8 @@
 import String.Ukrainian.UniquenessPeriods
 
 #ifdef __GLASGOW_HASKELL__
-#if __GLASGOW_HASKELL__<804
-/* code that applies only to GHC 8.2.* and lower versions */
+#if __GLASGOW_HASKELL__==708
+/* code that applies only to GHC 7.8.* */
 mconcat = concat
 #endif
 #endif
@@ -43,7 +43,7 @@
  | null xs = ([],[])
  | otherwise = 
     let ys = f xs
-        y2s = concat . g $ ys in (ys,y2s)
+        y2s = mconcat . g $ ys in (ys,y2s)
 
 -- | Being given two functions as parameters uses them to create a longer list of 'Int' then application of only one of them. Besides, it can take into 
 -- account the possible 0 and to create a non-negative list of 'Int' that can be used e. g. by 'DobutokO.Norms.splitNorm'.
@@ -59,5 +59,5 @@
 uniquenessP2 :: [[String]] -> [[String]]
 uniquenessP2 (yss:ysss) 
   | null ysss = [yss]
-  | otherwise = if length yss == 1 then uniquenessP2 ysss else (yss \\ [concat . take 1 . concat . take 1 $ ysss]):uniquenessP2 ysss
+  | otherwise = if length yss == 1 then uniquenessP2 ysss else (yss \\ [mconcat . take 1 . mconcat . take 1 $ ysss]):uniquenessP2 ysss
 uniquenessP2 _ = []
diff --git a/dobutokO-poetry.cabal b/dobutokO-poetry.cabal
--- a/dobutokO-poetry.cabal
+++ b/dobutokO-poetry.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                dobutokO-poetry
-version:             0.13.0.0
+version:             0.14.0.0
 synopsis:            Helps to order the 7 or less Ukrainian words to obtain somewhat suitable for poetry or music text
 description:         Helps to order the 7 or less Ukrainian words (or their concatenations) to obtain somewhat suitable for poetry or music text. Can be also used as a research instrument with generalized functions.