diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
 # Changelog for sandwich-slack
 
 ## Unreleased changes
+
+## 0.1.0.6
+
+* Relax base bound so we can build on GHC 9
diff --git a/sandwich-slack.cabal b/sandwich-slack.cabal
--- a/sandwich-slack.cabal
+++ b/sandwich-slack.cabal
@@ -1,15 +1,15 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.33.0.
+-- This file has been generated from package.yaml by hpack version 0.34.4.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 87b67607e636cc36cd53424fdd2c45e855177f019d67d230fd8d6d77bdbc6f3f
+-- hash: 50f2c0f77f15237db2d29e2b36e0b9a3a2d553043aeeb460cd7fe04012530a42
 
 name:           sandwich-slack
-version:        0.1.0.4
+version:        0.1.0.6
 synopsis:       Sandwich integration with Slack
-description:    Please see the documentation at <https://codedownio.github.io/sandwich/docs/extensions/sandwich-slack>
+description:    Please see the <https://codedownio.github.io/sandwich/docs/extensions/sandwich-slack documentation>.
 category:       Testing
 homepage:       https://codedownio.github.io/sandwich
 bug-reports:    https://github.com/codedownio/sandwich/issues
@@ -41,7 +41,7 @@
   ghc-options: -W
   build-depends:
       aeson
-    , base <4.15
+    , base <5
     , bytestring
     , containers
     , lens
@@ -68,7 +68,7 @@
   ghc-options: -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       aeson
-    , base <4.15
+    , base <5
     , bytestring
     , containers
     , lens
@@ -97,7 +97,7 @@
   ghc-options: -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       aeson
-    , base <4.15
+    , base <5
     , bytestring
     , containers
     , lens
@@ -107,7 +107,6 @@
     , safe
     , safe-exceptions
     , sandwich
-    , sandwich-slack
     , stm
     , string-interpolate
     , text
diff --git a/src/Test/Sandwich/Formatters/Slack.hs b/src/Test/Sandwich/Formatters/Slack.hs
--- a/src/Test/Sandwich/Formatters/Slack.hs
+++ b/src/Test/Sandwich/Formatters/Slack.hs
@@ -8,6 +8,8 @@
 {-# LANGUAGE FlexibleContexts #-}
 
 -- | The Slack formatter shows live-updating test progress and failures by sending messages to a Slack channel.
+--
+-- Documentation can be found <https://codedownio.github.io/sandwich/docs/formatters/slack here>.
 
 module Test.Sandwich.Formatters.Slack (
   defaultSlackFormatter