diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -353,3 +353,7 @@
 * Thirty-eigth version. Added new datatype Params to DobutokO.Sound.Functional module. Added new generalized functions to work with Params to 
 DobutokO.Sound.Functional and DobutokO.Sound modules. They allow to use tonalities in compositions. Although a great part of the already existed 
 functions in the modules provides very similar behaviour to the some variant of the new ones they still are left in the modules.
+
+## 0.38.1.0 -- 2020-05-04
+
+* Thirty-eigth version revised A. Fixed issue with being not exported constructors in a Params datatype. 
diff --git a/DobutokO/Sound/Functional.hs b/DobutokO/Sound/Functional.hs
--- a/DobutokO/Sound/Functional.hs
+++ b/DobutokO/Sound/Functional.hs
@@ -12,7 +12,7 @@
 {-# OPTIONS_GHC -threaded #-}
 
 module DobutokO.Sound.Functional (
-  Params
+  Params (..)
   -- * Type synonyms with different semantics
   , SoundsO
   , OvertonesO
diff --git a/dobutokO2.cabal b/dobutokO2.cabal
--- a/dobutokO2.cabal
+++ b/dobutokO2.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                dobutokO2
-version:             0.38.0.0
+version:             0.38.1.0
 synopsis:            Helps to create experimental music from a file (or its part) and a Ukrainian text.
 description:         It can also generate a timbre for the notes. Uses SoX inside.
 homepage:            https://hackage.haskell.org/package/dobutokO2