diff --git a/.gitignore b/.gitignore
--- a/.gitignore
+++ b/.gitignore
@@ -9,6 +9,7 @@
 TAGS
 /.idea/
 /.dir-locals.el
-
 src/highlight.js
-src/style.css
+src/style.css/dist*
+/result*
+/dist*
diff --git a/pretty-types.cabal b/pretty-types.cabal
--- a/pretty-types.cabal
+++ b/pretty-types.cabal
@@ -1,5 +1,6 @@
+cabal-version:       >=1.22
 name:                pretty-types
-version:             0.2.3.1
+version:             0.4.0.0
 synopsis:            A small pretty printing DSL for complex types.
 description:         Please see README.md
 homepage:            https://github.com/sheyll/pretty-types#readme
@@ -7,7 +8,7 @@
 license-file:         LICENSE
 author:              Sven Heyll
 maintainer:          sven.heyll@gmail.com
-copyright:           2016 Sven Heyll
+copyright:           2016-2021 Sven Heyll
 category:            Text
 build-type:          Simple
 extra-source-files:   README.md
@@ -15,7 +16,6 @@
                     , .travis.yml
                     , .gitignore
                     , ChangeLog.md
-cabal-version:       >=1.10
 
 library
   hs-source-dirs:      src
@@ -57,7 +57,6 @@
   type:                exitcode-stdio-1.0
   ghc-options:         -Wall
   hs-source-dirs:      spec
-  default-language:    Haskell2010
   main-is:             PrettyTypesSpec.hs
   build-depends:       base >= 4.9 && < 5
                      , hspec
@@ -91,8 +90,7 @@
                      , TypeInType
                      , TypeOperators
                      , TypeSynonymInstances
-  ghc-options:       -Wall -O0 -j +RTS -A256m -n2m -RTS
-                     -fwarn-unused-binds -fno-warn-unused-do-bind -fno-warn-missing-signatures
+  ghc-options:       -Wall -fno-warn-unused-do-bind -fno-warn-missing-signatures
 
 source-repository head
   type:     git
diff --git a/src/Data/Type/Pretty.hs b/src/Data/Type/Pretty.hs
--- a/src/Data/Type/Pretty.hs
+++ b/src/Data/Type/Pretty.hs
@@ -119,7 +119,7 @@
 -- | Pretty print either types of kind 'PrettyType' or any other type with a
 -- 'ToPretty' instance.
 showPretty
-  :: forall proxy (t :: k) . PrettyTypeShow (ToPretty t)
+  :: forall k proxy (t :: k) . PrettyTypeShow (ToPretty t)
   => proxy t  -- ^ A proxy to the type to print. A 'ToPretty' instance for t must exists.
   -> String
 showPretty _ = snd $ evalRWS (ptShow (Proxy :: Proxy (ToPretty t))) 0 AtBeginningOfLine
diff --git a/stack.yaml b/stack.yaml
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,4 +1,4 @@
-resolver: lts-7.0
+resolver: lts-16.31
 packages:
 - '.'
 extra-deps: []