diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## [0.5.0.1] - 2019-09-23
+
+### Changed
+
+* Improved the cabal file
+* Used `++` instead of `<>` for a string, for compatibility purposes
+
 ## [0.5.0.0] - 2019-09-23
 
 ### Added
diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2016 Tom Sydney Kerckhove
+Copyright (c) 2016-2020 Tom Sydney Kerckhove
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/src/Data/Validity/Map.hs b/src/Data/Validity/Map.hs
--- a/src/Data/Validity/Map.hs
+++ b/src/Data/Validity/Map.hs
@@ -4,10 +4,9 @@
   ( decorateMap
   ) where
 
-import Data.Validity
-
 import Data.Map (Map)
 import qualified Data.Map as M
+import Data.Validity
 
 -- | A 'Map' of things is valid if all the keys and values are valid and the 'Map' itself
 -- is valid.
@@ -22,4 +21,4 @@
 decorateMap :: Show k => Map k v -> (k -> v -> Validation) -> Validation
 decorateMap m func = M.foldMapWithKey go m
   where
-    go k v = decorate ("The key/value at key " <> show k) $ func k v
+    go k v = decorate ("The key/value at key " ++ show k) $ func k v
diff --git a/validity-containers.cabal b/validity-containers.cabal
--- a/validity-containers.cabal
+++ b/validity-containers.cabal
@@ -1,22 +1,20 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.31.2.
+-- This file has been generated from package.yaml by hpack version 0.33.0.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: f1bc39d3211c9add5e9e1ed029815126baa1c40c73a70873db227d02c45b103f
+-- hash: e18d352553d6a22b91568f375e2881d9d63c6e00fbc30a1e7f3498c3b2690611
 
 name:           validity-containers
-version:        0.5.0.0
+version:        0.5.0.1
 synopsis:       Validity instances for containers
-description:    Please see README.md
 category:       Validity
 homepage:       https://github.com/NorfairKing/validity#readme
 bug-reports:    https://github.com/NorfairKing/validity/issues
 author:         Tom Sydney Kerckhove
-maintainer:     syd.kerckhove@gmail.com,
-                nick.van.den.broeck666@gmail.com
-copyright:      Copyright: (c) 2016-2018 Tom Sydney Kerckhove
+maintainer:     syd@cs-syd.eu
+copyright:      Copyright: (c) 2016-2020 Tom Sydney Kerckhove
 license:        MIT
 license-file:   LICENSE
 build-type:     Simple
@@ -30,10 +28,10 @@
 library
   exposed-modules:
       Data.Validity.Containers
-      Data.Validity.Tree
       Data.Validity.Map
       Data.Validity.Sequence
       Data.Validity.Set
+      Data.Validity.Tree
   other-modules:
       Paths_validity_containers
   hs-source-dirs: