diff --git a/one-liner.cabal b/one-liner.cabal
--- a/one-liner.cabal
+++ b/one-liner.cabal
@@ -1,6 +1,6 @@
 cabal-version:        2.0
 name:                 one-liner
-version:              2.1
+version:              2.1.1
 synopsis:             Constraint-based generics
 description:          Write short and concise generic instances of type classes.
                       one-liner is particularly useful for writing default
@@ -13,15 +13,17 @@
 maintainer:           sjoerd@w3future.com
 category:             Generics
 build-type:           Simple
-tested-with:          GHC==9.0.1, GHC==9.2.1
+tested-with:          GHC==9.6.7, GHC==9.8.4, GHC==9.10.3, GHC==9.12.2, GHC==9.14.1
 
 extra-source-files:
   examples/*.hs
+extra-doc-files:
   CHANGELOG
 
 library
   hs-source-dirs:     src
   default-language:   Haskell2010
+  ghc-options:        -Wall
 
   exposed-modules:
     Generics.OneLiner
@@ -32,17 +34,16 @@
 
   build-depends:
       base          >= 4.9 && < 5
-    , transformers  >= 0.5 && < 0.6
     , contravariant >= 1.4 && < 1.6
-    , ghc-prim      >= 0.5 && < 1.0
-    , bifunctors    >= 5.4 && < 6.0
-    , profunctors   >= 5.2 && < 6.0
+    , ghc-prim      >= 0.5 && < 1
+    , bifunctors    >= 5.4 && < 6
+    , profunctors   >= 5.2 && < 6
     , tagged        >= 0.8 && < 0.9
-    , linear-base   >= 0.1 && < 1.0
+    , linear-base   >= 0.1 && < 1
 
 source-repository head
   type:     git
-  location: git://github.com/sjoerdvisscher/one-liner.git
+  location: https://github.com/sjoerdvisscher/one-liner
 
 test-suite unittests
   hs-source-dirs:  test
@@ -51,7 +52,6 @@
 
   build-depends:
       base
-    , contravariant
     , HUnit
     , one-liner
 
diff --git a/src/Generics/OneLiner/Internal/Unary.hs b/src/Generics/OneLiner/Internal/Unary.hs
--- a/src/Generics/OneLiner/Internal/Unary.hs
+++ b/src/Generics/OneLiner/Internal/Unary.hs
@@ -13,6 +13,7 @@
   , RankNTypes
   , LinearTypes
   , TypeFamilies
+  , TypeOperators
   , ConstraintKinds
   , FlexibleContexts
   , TypeApplications