diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,4 +1,7 @@
 # Changelog for subcategories
 
+## 0.1.1.0
+Support GHC >= 9.0
+
 ## 0.1.0.0
 Initial Release
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,5 +1,9 @@
 # The `subcategories` package
 
+![Haskell CI](https://github.com/konn/subcategories/workflows/Haskell%20CI/badge.svg)
+![Hackage](https://img.shields.io/hackage/v/subcategories)
+![Hackage-Deps](https://img.shields.io/hackage-deps/v/subcategories)
+
 This package provides variants of functor-like structures,
 with domain types are constrained.
 In particular, this package provides an abstraction for functorial
diff --git a/src/Control/Subcategory/Wrapper/Internal.hs b/src/Control/Subcategory/Wrapper/Internal.hs
--- a/src/Control/Subcategory/Wrapper/Internal.hs
+++ b/src/Control/Subcategory/Wrapper/Internal.hs
@@ -52,4 +52,4 @@
   :: (Coercible (WrapMono mono (Element mono)) mono => r)
   -> r
 {-# INLINE withMonoCoercible #-}
-withMonoCoercible = id
+withMonoCoercible = \x -> x
diff --git a/subcategories.cabal b/subcategories.cabal
--- a/subcategories.cabal
+++ b/subcategories.cabal
@@ -4,10 +4,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 06bb5130d08da403db0bdee15f708a050dca4d9ba1adb757dd932c9586b3b0c2
+-- hash: fe6bc4de5931551cb2eb584dcbd9ed3c9ed1692f00c9fa0323cc2b6ddb28fb61
 
 name:           subcategories
-version:        0.1.0.0
+version:        0.1.1.0
 synopsis:       Subcategories induced by class constraints
 description:    Please see the README on GitHub at <https://github.com/konn/subcategories#readme>
 category:       Data
@@ -18,7 +18,7 @@
 copyright:      2018 (c) Hiromi ISHII
 license:        BSD3
 license-file:   LICENSE
-tested-with:    GHC == 8.6.5, GHC == 8.8.3, GHC == 8.10.1
+tested-with:    GHC == 8.6.5, GHC == 8.8.3, GHC == 8.10.3, GHC == 9.0.1
 build-type:     Simple
 extra-source-files:
     README.md