diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7a988ae..3ef12ba 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -20,7 +20,7 @@ jobs:
       matrix:
         os: [ubuntu-latest]
         cabal: [latest]
-        ghc: ['8.6', '8.8', '8.10', '9.0']
+        ghc: ['8.8', '8.10', '9.0', '9.2']
       fail-fast: false
 
     steps:
diff --git a/changelog.md b/changelog.md
index 8e41781..f786d2d 100644
--- a/changelog.md
+++ b/changelog.md
@@ -2,6 +2,7 @@
 
 ## WIP
 - Correct author name
+- Squash warnings for newer GHCs
 
 ## [0.12.5] - 2021-05-29
 - Tweak test suite to fix #35
diff --git a/default.nix b/default.nix
index 18de653..8a6b0b7 100644
--- a/default.nix
+++ b/default.nix
@@ -1,9 +1,4 @@
-{ nixpkgsSrc ? builtins.fetchTarball {
-  url =
-    "https://github.com/NixOS/nixpkgs/archive/540dccb2aeaffa9dc69bfdc41c55abd7ccc6baa3.tar.gz"; # nixos-unstable
-  sha256 = "1j58m811w7xxjncf36hqcjqsfj979hkfcwx9wcrm3g3zbayavapg";
-}, pkgs ? import nixpkgsSrc { }, compiler ? null, extraOverrides ? _: _: { }
-, modifier ? x: x }:
+{ nixpkgsSrc ? <nixpkgs>, pkgs ? import nixpkgsSrc { }, compiler ? null }:
 
 let
   haskellPackages = if compiler == null then
@@ -14,8 +9,5 @@ let
 in haskellPackages.developPackage {
   name = "";
   root = pkgs.nix-gitignore.gitignoreSource [ ] ./.;
-  overrides = with pkgs.haskell.lib;
-    pkgs.lib.composeExtensions (_self: _super: { }) extraOverrides;
-  inherit modifier;
+  overrides = _self: _super: { };
 }
-
diff --git a/src/Data/CReal/Internal.hs b/src/Data/CReal/Internal.hs
index b81d024..1796fbd 100644
--- a/src/Data/CReal/Internal.hs
+++ b/src/Data/CReal/Internal.hs
@@ -768,7 +768,7 @@ powerSeries q termsAtPrecision x = crMemoize
                 p' = p + d
                 p'' = p' + d
                 m = atPrecision x p''
-                xs = (%1) <$> iterate (\e -> m * e /^ p'') (bit p')
+                xs = (% 1) <$> iterate (\e -> m * e /^ p'') (bit p')
                 r = sum . take (t + 1) . fmap (round . (* fromInteger (bit d))) $ zipWith (*) q xs
             in r /^ (2 * d))
 
diff --git a/stack-7.10.2.yaml b/stack-7.10.2.yaml
deleted file mode 100644
index 7cbdfb8..0000000
--- a/stack-7.10.2.yaml
+++ /dev/null
@@ -1,7 +0,0 @@
-resolver: lts-3.22
-packages:
-- '.'
-allow-newer: true
-extra-deps:
-- QuickCheck-2.14@sha256:a1bac79e48b36d5bccd771e981058c44707f440156a0a411ebdcfec8cfccfda9,6982
-- splitmix-0.0.4@sha256:fb9bb8b54a2e76c8a021fe5c4c3798047e1f60e168379a1f80693047fe00ad0e,4813
diff --git a/stack-7.10.2.yaml.lock b/stack-7.10.2.yaml.lock
deleted file mode 100644
index d0ed797..0000000
--- a/stack-7.10.2.yaml.lock
+++ /dev/null
@@ -1,26 +0,0 @@
-# This file was autogenerated by Stack.
-# You should not edit this file by hand.
-# For more information, please see the documentation at:
-#   https://docs.haskellstack.org/en/stable/lock_files
-
-packages:
-- completed:
-    hackage: QuickCheck-2.14@sha256:a1bac79e48b36d5bccd771e981058c44707f440156a0a411ebdcfec8cfccfda9,6982
-    pantry-tree:
-      size: 2203
-      sha256: 1c8b0f1ff061117c78ddb69cbed242faf313a427c03e5c84233aa33e7e58a5cb
-  original:
-    hackage: QuickCheck-2.14@sha256:a1bac79e48b36d5bccd771e981058c44707f440156a0a411ebdcfec8cfccfda9,6982
-- completed:
-    hackage: splitmix-0.0.4@sha256:fb9bb8b54a2e76c8a021fe5c4c3798047e1f60e168379a1f80693047fe00ad0e,4813
-    pantry-tree:
-      size: 872
-      sha256: e58892088b95190bfb59a7c0803f7ef65338e57fc9b938d7c166563605003902
-  original:
-    hackage: splitmix-0.0.4@sha256:fb9bb8b54a2e76c8a021fe5c4c3798047e1f60e168379a1f80693047fe00ad0e,4813
-snapshots:
-- completed:
-    size: 285839
-    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/3/22.yaml
-    sha256: 2dbef28cadb2ba699f34699506150cc9f231278bf8791ff6d80cb00800128d3a
-  original: lts-3.22
diff --git a/stack-7.10.3.yaml b/stack-7.10.3.yaml
deleted file mode 100644
index 0e40c78..0000000
--- a/stack-7.10.3.yaml
+++ /dev/null
@@ -1,6 +0,0 @@
-resolver: lts-6.35
-packages:
-- '.'
-extra-deps:
-- QuickCheck-2.14@sha256:a1bac79e48b36d5bccd771e981058c44707f440156a0a411ebdcfec8cfccfda9,6982
-- splitmix-0.0.4@sha256:fb9bb8b54a2e76c8a021fe5c4c3798047e1f60e168379a1f80693047fe00ad0e,4813
diff --git a/stack-7.10.3.yaml.lock b/stack-7.10.3.yaml.lock
deleted file mode 100644
index b7db384..0000000
--- a/stack-7.10.3.yaml.lock
+++ /dev/null
@@ -1,26 +0,0 @@
-# This file was autogenerated by Stack.
-# You should not edit this file by hand.
-# For more information, please see the documentation at:
-#   https://docs.haskellstack.org/en/stable/lock_files
-
-packages:
-- completed:
-    hackage: QuickCheck-2.14@sha256:a1bac79e48b36d5bccd771e981058c44707f440156a0a411ebdcfec8cfccfda9,6982
-    pantry-tree:
-      size: 2203
-      sha256: 1c8b0f1ff061117c78ddb69cbed242faf313a427c03e5c84233aa33e7e58a5cb
-  original:
-    hackage: QuickCheck-2.14@sha256:a1bac79e48b36d5bccd771e981058c44707f440156a0a411ebdcfec8cfccfda9,6982
-- completed:
-    hackage: splitmix-0.0.4@sha256:fb9bb8b54a2e76c8a021fe5c4c3798047e1f60e168379a1f80693047fe00ad0e,4813
-    pantry-tree:
-      size: 872
-      sha256: e58892088b95190bfb59a7c0803f7ef65338e57fc9b938d7c166563605003902
-  original:
-    hackage: splitmix-0.0.4@sha256:fb9bb8b54a2e76c8a021fe5c4c3798047e1f60e168379a1f80693047fe00ad0e,4813
-snapshots:
-- completed:
-    size: 428787
-    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/6/35.yaml
-    sha256: f2ce58e96ad78750c355afc8fcd0bfbd06c8e1381050c59bc5c934577ebef872
-  original: lts-6.35
diff --git a/stack-8.2.2.yaml b/stack-8.2.2.yaml
deleted file mode 100644
index da8a494..0000000
--- a/stack-8.2.2.yaml
+++ /dev/null
@@ -1,5 +0,0 @@
-resolver: lts-11.22
-packages:
-- '.'
-extra-deps:
-- memoize-0.8.1@sha256:2146197c639c126796d850cb4457b24cfeb6966d6d878825f855aafce31f8874,1601
diff --git a/stack-8.2.2.yaml.lock b/stack-8.2.2.yaml.lock
deleted file mode 100644
index e4a31c6..0000000
--- a/stack-8.2.2.yaml.lock
+++ /dev/null
@@ -1,19 +0,0 @@
-# This file was autogenerated by Stack.
-# You should not edit this file by hand.
-# For more information, please see the documentation at:
-#   https://docs.haskellstack.org/en/stable/lock_files
-
-packages:
-- completed:
-    hackage: memoize-0.8.1@sha256:2146197c639c126796d850cb4457b24cfeb6966d6d878825f855aafce31f8874,1601
-    pantry-tree:
-      size: 473
-      sha256: 598188857937054d2cc4ac91aee580944d750e91120756507891d09e02056066
-  original:
-    hackage: memoize-0.8.1@sha256:2146197c639c126796d850cb4457b24cfeb6966d6d878825f855aafce31f8874,1601
-snapshots:
-- completed:
-    size: 527836
-    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/11/22.yaml
-    sha256: 341870ac98d8a9f8f77c4adf2e9e0b22063e264a7fbeb4c85b7af5f380dac60e
-  original: lts-11.22
diff --git a/stack-8.4.4.yaml b/stack-8.4.4.yaml
deleted file mode 100644
index 8a1397f..0000000
--- a/stack-8.4.4.yaml
+++ /dev/null
@@ -1,5 +0,0 @@
-resolver: lts-12.26
-packages:
-- '.'
-extra-deps:
-- memoize-0.8.1@sha256:2146197c639c126796d850cb4457b24cfeb6966d6d878825f855aafce31f8874,1601
diff --git a/stack-8.4.4.yaml.lock b/stack-8.4.4.yaml.lock
deleted file mode 100644
index 137f409..0000000
--- a/stack-8.4.4.yaml.lock
+++ /dev/null
@@ -1,19 +0,0 @@
-# This file was autogenerated by Stack.
-# You should not edit this file by hand.
-# For more information, please see the documentation at:
-#   https://docs.haskellstack.org/en/stable/lock_files
-
-packages:
-- completed:
-    hackage: memoize-0.8.1@sha256:2146197c639c126796d850cb4457b24cfeb6966d6d878825f855aafce31f8874,1601
-    pantry-tree:
-      size: 473
-      sha256: 598188857937054d2cc4ac91aee580944d750e91120756507891d09e02056066
-  original:
-    hackage: memoize-0.8.1@sha256:2146197c639c126796d850cb4457b24cfeb6966d6d878825f855aafce31f8874,1601
-snapshots:
-- completed:
-    size: 509471
-    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/12/26.yaml
-    sha256: 95f014df58d0679b1c4a2b7bf2b652b61da8d30de5f571abb0d59015ef678646
-  original: lts-12.26
diff --git a/stack-8.6.5.yaml b/stack-8.6.5.yaml
deleted file mode 100644
index 96463c1..0000000
--- a/stack-8.6.5.yaml
+++ /dev/null
@@ -1,5 +0,0 @@
-resolver: lts-14.27
-packages:
-- '.'
-extra-deps:
-- memoize-0.8.1@sha256:2146197c639c126796d850cb4457b24cfeb6966d6d878825f855aafce31f8874,1601
diff --git a/stack-8.6.5.yaml.lock b/stack-8.6.5.yaml.lock
deleted file mode 100644
index 962c20b..0000000
--- a/stack-8.6.5.yaml.lock
+++ /dev/null
@@ -1,19 +0,0 @@
-# This file was autogenerated by Stack.
-# You should not edit this file by hand.
-# For more information, please see the documentation at:
-#   https://docs.haskellstack.org/en/stable/lock_files
-
-packages:
-- completed:
-    hackage: memoize-0.8.1@sha256:2146197c639c126796d850cb4457b24cfeb6966d6d878825f855aafce31f8874,1601
-    pantry-tree:
-      size: 473
-      sha256: 598188857937054d2cc4ac91aee580944d750e91120756507891d09e02056066
-  original:
-    hackage: memoize-0.8.1@sha256:2146197c639c126796d850cb4457b24cfeb6966d6d878825f855aafce31f8874,1601
-snapshots:
-- completed:
-    size: 524996
-    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/14/27.yaml
-    sha256: 7ea31a280c56bf36ff591a7397cc384d0dff622e7f9e4225b47d8980f019a0f0
-  original: lts-14.27
diff --git a/test/Test.hs b/test/Test.hs
index b5399b5..8de552d 100644
--- a/test/Test.hs
+++ b/test/Test.hs
@@ -13,7 +13,6 @@ import           Data.List             (inits)
 import           Data.Maybe            (fromJust)
 import           Data.Proxy
 import           Data.Ratio            ((%))
-import           Data.Semigroup
 import           GHC.TypeNats
 import           Numeric.Natural
 import           Test.Tasty            (TestTree, defaultMain, testGroup)
diff --git a/test/Test/QuickCheck/Classes/Extra.hs b/test/Test/QuickCheck/Classes/Extra.hs
index ca763f8..68374d1 100644
--- a/test/Test/QuickCheck/Classes/Extra.hs
+++ b/test/Test/QuickCheck/Classes/Extra.hs
@@ -17,7 +17,7 @@ module Test.QuickCheck.Classes.Extra
   ) where
 
 import Data.Group (invert, Group, Abelian)
-import Data.Monoid ((<>), Sum(..), Product)
+import Data.Monoid (Sum(..), Product)
 import Test.QuickCheck.Extra (Arbitrary, (<=>), (==>))
 import Test.QuickCheck.Modifiers (NonZero)
 import Test.QuickCheck.Checkers (commutes, transitive, EqProp, (=-=), BinRel)
diff --git a/test/Test/QuickCheck/Extra.hs b/test/Test/QuickCheck/Extra.hs
index 93c17d0..30576cb 100644
--- a/test/Test/QuickCheck/Extra.hs
+++ b/test/Test/QuickCheck/Extra.hs
@@ -14,7 +14,6 @@ module Test.QuickCheck.Extra
 
 import Test.QuickCheck
 import Test.QuickCheck.Checkers (EqProp)
-import Test.QuickCheck.Modifiers (NonZero(..), Positive(..))
 import System.Random (Random)
 
 deriving instance Num a => Num (NonZero a)