diff --git a/.ghci b/.ghci
deleted file mode 100644
--- a/.ghci
+++ /dev/null
@@ -1,1 +0,0 @@
-:set -isrc -idist/build/autogen -optP-include -optPdist/build/autogen/cabal_macros.h
diff --git a/.gitignore b/.gitignore
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,5 @@
 dist
-dist-newstyle
+dist-*
 docs
 wiki
 TAGS
diff --git a/.hlint.yaml b/.hlint.yaml
new file mode 100644
--- /dev/null
+++ b/.hlint.yaml
@@ -0,0 +1,4 @@
+- arguments: [--cpp-define=HLINT, --cpp-ansi]
+
+- ignore: {name: Eta reduce}
+- ignore: {name: Use import/export shortcut}
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
--- a/.travis.yml
+++ /dev/null
@@ -1,164 +0,0 @@
-# This Travis job script has been generated by a script via
-#
-#   runghc make_travis_yml_2.hs '-o' '.travis.yml' '--ghc-head' '--irc-channel=irc.freenode.org#haskell-lens' '--no-no-tests-no-bench' '--no-unconstrained' 'cabal.project'
-#
-# For more information, see https://github.com/hvr/multi-ghc-travis
-#
-language: c
-sudo: false
-
-git:
-  submodules: false  # whether to recursively clone submodules
-
-notifications:
-  irc:
-    channels:
-      - "irc.freenode.org#haskell-lens"
-    skip_join: true
-    template:
-      - "\x0313comonad\x03/\x0306%{branch}\x03 \x0314%{commit}\x03 %{build_url} %{message}"
-
-cache:
-  directories:
-    - $HOME/.cabal/packages
-    - $HOME/.cabal/store
-
-before_cache:
-  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/build-reports.log
-  # remove files that are regenerated by 'cabal update'
-  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/00-index.*
-  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/*.json
-  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/01-index.cache
-  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/01-index.tar
-  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/01-index.tar.idx
-
-  - rm -rfv $HOME/.cabal/packages/head.hackage
-
-matrix:
-  include:
-    - compiler: "ghc-8.6.1"
-      env: GHCHEAD=true
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-head,ghc-8.6.1], sources: [hvr-ghc]}}
-    - compiler: "ghc-8.4.3"
-    # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-8.4.3], sources: [hvr-ghc]}}
-    - compiler: "ghc-8.2.2"
-    # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-8.2.2], sources: [hvr-ghc]}}
-    - compiler: "ghc-8.0.2"
-    # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-8.0.2], sources: [hvr-ghc]}}
-    - compiler: "ghc-7.10.3"
-    # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-7.10.3], sources: [hvr-ghc]}}
-    - compiler: "ghc-7.8.4"
-    # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-7.8.4], sources: [hvr-ghc]}}
-    - compiler: "ghc-7.6.3"
-      env: HADDOCK=false # Work around https://github.com/haskell/haddock/issues/242
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-7.6.3], sources: [hvr-ghc]}}
-    - compiler: "ghc-7.4.2"
-    # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-7.4.2], sources: [hvr-ghc]}}
-    - compiler: "ghc-7.2.2"
-    # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-7.2.2], sources: [hvr-ghc]}}
-    - compiler: "ghc-7.0.4"
-    # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-7.0.4], sources: [hvr-ghc]}}
-    - compiler: "ghc-head"
-      env: GHCHEAD=true
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-head,ghc-head], sources: [hvr-ghc]}}
-
-  allow_failures:
-    - compiler: "ghc-head"
-    - compiler: "ghc-7.0.4"
-    - compiler: "ghc-7.2.2"
-    - compiler: "ghc-8.6.1"
-
-before_install:
-  - HC=${CC}
-  - HCPKG=${HC/ghc/ghc-pkg}
-  - unset CC
-  - ROOTDIR=$(pwd)
-  - mkdir -p $HOME/.local/bin
-  - "PATH=/opt/ghc/bin:/opt/ghc-ppa-tools/bin:$HOME/local/bin:$PATH"
-  - HCNUMVER=$(( $(${HC} --numeric-version|sed -E 's/([0-9]+)\.([0-9]+)\.([0-9]+).*/\1 * 10000 + \2 * 100 + \3/') ))
-  - echo $HCNUMVER
-
-install:
-  - cabal --version
-  - echo "$(${HC} --version) [$(${HC} --print-project-git-commit-id 2> /dev/null || echo '?')]"
-  - BENCH=${BENCH---enable-benchmarks}
-  - TEST=${TEST---enable-tests}
-  - HADDOCK=${HADDOCK-true}
-  - UNCONSTRAINED=${UNCONSTRAINED-true}
-  - NOINSTALLEDCONSTRAINTS=${NOINSTALLEDCONSTRAINTS-false}
-  - GHCHEAD=${GHCHEAD-false}
-  - travis_retry cabal update -v
-  - "sed -i.bak 's/^jobs:/-- jobs:/' ${HOME}/.cabal/config"
-  - rm -fv cabal.project cabal.project.local
-  # Overlay Hackage Package Index for GHC HEAD: https://github.com/hvr/head.hackage
-  - |
-    if $GHCHEAD; then
-      sed -i 's/-- allow-newer: .*/allow-newer: *:base/' ${HOME}/.cabal/config
-      for pkg in $($HCPKG list --simple-output); do pkg=$(echo $pkg | sed 's/-[^-]*$//'); sed -i "s/allow-newer: /allow-newer: *:$pkg, /" ${HOME}/.cabal/config; done
-
-      echo 'repository head.hackage'                                                        >> ${HOME}/.cabal/config
-      echo '   url: http://head.hackage.haskell.org/'                                       >> ${HOME}/.cabal/config
-      echo '   secure: True'                                                                >> ${HOME}/.cabal/config
-      echo '   root-keys: 07c59cb65787dedfaef5bd5f987ceb5f7e5ebf88b904bbd4c5cbdeb2ff71b740' >> ${HOME}/.cabal/config
-      echo '              2e8555dde16ebd8df076f1a8ef13b8f14c66bad8eafefd7d9e37d0ed711821fb' >> ${HOME}/.cabal/config
-      echo '              8f79fd2389ab2967354407ec852cbe73f2e8635793ac446d09461ffb99527f6e' >> ${HOME}/.cabal/config
-      echo '   key-threshold: 3'                                                            >> ${HOME}/.cabal.config
-
-      grep -Ev -- '^\s*--' ${HOME}/.cabal/config | grep -Ev '^\s*$'
-
-      cabal new-update head.hackage -v
-    fi
-  - grep -Ev -- '^\s*--' ${HOME}/.cabal/config | grep -Ev '^\s*$'
-  - "printf 'packages: \".\" \"./examples\"\\n' > cabal.project"
-  - touch cabal.project.local
-  - "if ! $NOINSTALLEDCONSTRAINTS; then for pkg in $($HCPKG list --simple-output); do echo $pkg | sed 's/^/constraints: /' | sed 's/-[^-]*$/ installed/' >> cabal.project.local; done; fi"
-  - cat cabal.project || true
-  - cat cabal.project.local || true
-  - if [ -f "./configure.ac" ]; then
-      (cd "." && autoreconf -i);
-    fi
-  - if [ -f "./examples/configure.ac" ]; then
-      (cd "./examples" && autoreconf -i);
-    fi
-  - rm -f cabal.project.freeze
-  - cabal new-build -w ${HC} ${TEST} ${BENCH} --project-file="cabal.project" --dep -j2 all
-  - rm -rf .ghc.environment.* "."/dist "./examples"/dist
-  - DISTDIR=$(mktemp -d /tmp/dist-test.XXXX)
-
-# Here starts the actual work to be performed for the package under test;
-# any command which exits with a non-zero exit code causes the build to fail.
-script:
-  # test that source-distributions can be generated
-  - (cd "." && cabal sdist)
-  - (cd "./examples" && cabal sdist)
-  - mv "."/dist/comonad-*.tar.gz "./examples"/dist/comonad-examples-*.tar.gz ${DISTDIR}/
-  - cd ${DISTDIR} || false
-  - find . -maxdepth 1 -name '*.tar.gz' -exec tar -xvf '{}' \;
-  - "printf 'packages: comonad-*/*.cabal comonad-examples-*/*.cabal\\n' > cabal.project"
-  - touch cabal.project.local
-  - "if ! $NOINSTALLEDCONSTRAINTS; then for pkg in $($HCPKG list --simple-output); do echo $pkg | sed 's/^/constraints: /' | sed 's/-[^-]*$/ installed/' >> cabal.project.local; done; fi"
-  - cat cabal.project || true
-  - cat cabal.project.local || true
-
-  # build & run tests, build benchmarks
-  - cabal new-build -w ${HC} ${TEST} ${BENCH} all
-  - if [ "x$TEST" = "x--enable-tests" ]; then cabal new-test -w ${HC} ${TEST} ${BENCH} all; fi
-
-  # cabal check
-  - (cd comonad-* && cabal check)
-  - (cd comonad-examples-* && cabal check)
-
-  # haddock
-  - rm -rf ./dist-newstyle
-  - if $HADDOCK; then cabal new-haddock -w ${HC} ${TEST} ${BENCH} all; else echo "Skipping haddock generation";fi
-
-# REGENDATA ["-o",".travis.yml","--ghc-head","--irc-channel=irc.freenode.org#haskell-lens","--no-no-tests-no-bench","--no-unconstrained","cabal.project"]
-# EOF
diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,35 @@
+5.0.10 [2026.01.10]
+-------------------
+* Support building with MicroHs.
+* Remove unused `transformers-compat` dependency.
+
+5.0.9 [2024.12.04]
+------------------
+* Drop support for pre-8.0 versions of GHC.
+
+5.0.8 [2020.12.30]
+-----------------
+* Explicitly mark modules as Safe or Trustworthy
+* The build-type has been changed from `Custom` to `Simple`.
+  To achieve this, the `doctests` test suite has been removed in favor of using [`cabal-docspec`](https://github.com/phadej/cabal-extras/tree/master/cabal-docspec) to run the doctests.
+
+5.0.7 [2020.12.15]
+------------------
+* Move `FunctorWithIndex (TracedT m w)` instance from `lens`.
+  This instance depends on the `indexed-traversable` package. This can be disabled using the flag of the same name.
+
+5.0.6 [2019.11.26]
+------------------
+* Achieve forward compatibility with
+  [GHC proposal 229](https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0229-whitespace-bang-patterns.rst).
+
+5.0.5 [2019.05.02]
+------------------
+* Raised the minimum `semigroups` version to 0.16.2. In addition, the
+  package will only be required at all for GHCs before 8.0.
+* Drop the `contravariant` flag from `comonad.cabal`, as `comonad` no longer
+  depends on the `contravariant` library.
+
 5.0.4 [2018.07.01]
 ------------------
 * Add `Comonad` instances for `Tagged s` with `s` of any kind. Before the
diff --git a/HLint.hs b/HLint.hs
deleted file mode 100644
--- a/HLint.hs
+++ /dev/null
@@ -1,4 +0,0 @@
-import "hint" HLint.HLint
-
-ignore "Eta reduce"
-ignore "Use import/export shortcut"
diff --git a/README.markdown b/README.markdown
--- a/README.markdown
+++ b/README.markdown
@@ -1,7 +1,7 @@
 comonad
 =======
 
-[![Hackage](https://img.shields.io/hackage/v/comonad.svg)](https://hackage.haskell.org/package/comonad) [![Build Status](https://secure.travis-ci.org/ekmett/comonad.svg?branch=master)](http://travis-ci.org/ekmett/comonad)
+[![Build Status](https://github.com/ekmett/comonad/workflows/Haskell-CI/badge.svg)](https://github.com/ekmett/comonad/actions?query=workflow%3AHaskell-CI)
 
 This package provides comonads, the categorical dual of monads. The typeclass
 provides three methods:  `extract`, `duplicate`, and `extend`.
diff --git a/Setup.lhs b/Setup.lhs
--- a/Setup.lhs
+++ b/Setup.lhs
@@ -1,34 +1,6 @@
 \begin{code}
-{-# LANGUAGE CPP #-}
-{-# OPTIONS_GHC -Wall #-}
 module Main (main) where
-
-#ifndef MIN_VERSION_cabal_doctest
-#define MIN_VERSION_cabal_doctest(x,y,z) 0
-#endif
-
-#if MIN_VERSION_cabal_doctest(1,0,0)
-
-import Distribution.Extra.Doctest ( defaultMainWithDoctests )
-main :: IO ()
-main = defaultMainWithDoctests "doctests"
-
-#else
-
-#ifdef MIN_VERSION_Cabal
--- If the macro is defined, we have new cabal-install,
--- but for some reason we don't have cabal-doctest in package-db
---
--- Probably we are running cabal sdist, when otherwise using new-build
--- workflow
-import Warning ()
-#endif
-
-import Distribution.Simple
-
+import Distribution.Simple (defaultMain)
 main :: IO ()
 main = defaultMain
-
-#endif
-
 \end{code}
diff --git a/Warning.hs b/Warning.hs
deleted file mode 100644
--- a/Warning.hs
+++ /dev/null
@@ -1,5 +0,0 @@
-module Warning
-  {-# WARNING ["You are configuring this package without cabal-doctest installed.",
-               "The doctests test-suite will not work as a result.",
-               "To fix this, install cabal-doctest before configuring."] #-}
-  () where
diff --git a/comonad.cabal b/comonad.cabal
--- a/comonad.cabal
+++ b/comonad.cabal
@@ -1,6 +1,6 @@
 name:          comonad
 category:      Control, Comonads
-version:       5.0.4
+version:       5.0.10
 license:       BSD3
 cabal-version: >= 1.10
 license-file:  LICENSE
@@ -13,31 +13,30 @@
                Copyright (C) 2004-2008 Dave Menendez
 synopsis:      Comonads
 description:   Comonads.
-build-type:    Custom
-tested-with:   GHC == 7.0.4, GHC == 7.2.2, GHC == 7.4.2, GHC == 7.6.3, GHC == 7.8.4, GHC == 7.10.3, GHC == 8.0.2, GHC == 8.2.2, GHC == 8.4.3, GHC == 8.6.1
+build-type:    Simple
+tested-with:   GHC == 8.0.2
+             , GHC == 8.2.2
+             , GHC == 8.4.4
+             , GHC == 8.6.5
+             , GHC == 8.8.4
+             , GHC == 8.10.7
+             , GHC == 9.0.2
+             , GHC == 9.2.8
+             , GHC == 9.4.8
+             , GHC == 9.6.7
+             , GHC == 9.8.4
+             , GHC == 9.10.3
+             , GHC == 9.12.2
+             , GHC == 9.14.1
 extra-source-files:
-  .ghci
   .gitignore
-  .travis.yml
+  .hlint.yaml
   .vim.custom
   coq/Store.v
   README.markdown
   CHANGELOG.markdown
   examples/History.hs
-  HLint.hs
-  Warning.hs
 
-custom-setup
-  setup-depends:
-    base          >= 4 && < 5,
-    Cabal,
-    cabal-doctest >= 1 && < 1.1
-
--- You can disable the doctests test suite with -f-test-doctests
-flag test-doctests
-  default: True
-  manual: True
-
 flag containers
   description:
     You can disable the use of the `containers` package using `-f-containers`.
@@ -46,24 +45,24 @@
   default: True
   manual: True
 
-flag contravariant
+flag distributive
   description:
-    You can disable the use of the `contravariant` package using `-f-contravariant`.
+    You can disable the use of the `distributive` package using `-f-distributive`.
     .
     Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.
     .
-    If disabled we will not supply instances of `Contravariant`
+    If disabled we will not supply instances of `Distributive`
     .
   default: True
   manual: True
 
-flag distributive
+flag indexed-traversable
   description:
-    You can disable the use of the `distributive` package using `-f-distributive`.
+    You can disable the use of the `indexed-traversable` package using `-f-indexed-traversable`.
     .
     Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.
     .
-    If disabled we will not supply instances of `Distributive`
+    If disabled we will not supply instances of `FunctorWithIndex`
     .
   default: True
   manual: True
@@ -71,7 +70,7 @@
 
 source-repository head
   type: git
-  location: git://github.com/ekmett/comonad.git
+  location: https://github.com/ekmett/comonad.git
 
 library
   hs-source-dirs: src
@@ -79,21 +78,24 @@
   ghc-options: -Wall
 
   build-depends:
-    base                >= 4       && < 5,
-    semigroups          >= 0.8.3.1 && < 1,
-    tagged              >= 0.7     && < 1,
-    transformers        >= 0.2     && < 0.6,
-    transformers-compat >= 0.3     && < 1
+    base                >= 4.9 && < 5,
+    tagged              >= 0.8.6.1 && < 1,
+    transformers        >= 0.5 && < 0.7
 
   if flag(containers)
-    build-depends: containers >= 0.3 && < 0.7
-
-  if flag(contravariant)
-    build-depends: contravariant >= 0.2.0.1 && < 2
+    build-depends: containers >= 0.3 && < 0.9
 
   if flag(distributive)
-    build-depends: distributive >= 0.2.2   && < 1
+    build-depends: distributive >= 0.5.2 && < 1
 
+  if flag(indexed-traversable)
+    build-depends: indexed-traversable >= 0.1.1 && < 0.2
+
+  if impl(ghc >= 9.0)
+    -- these flags may abort compilation with GHC-8.10
+    -- https://gitlab.haskell.org/ghc/ghc/-/merge_requests/3295
+    ghc-options: -Winferred-safe-imports -Wmissing-safe-haskell-mode
+
   exposed-modules:
     Control.Comonad
     Control.Comonad.Env
@@ -118,18 +120,3 @@
     FunctionalDependencies
     FlexibleInstances
     UndecidableInstances
-
-test-suite doctests
-  type:           exitcode-stdio-1.0
-  default-language: Haskell2010
-  main-is:        doctests.hs
-  ghc-options:    -Wall -threaded
-  hs-source-dirs: tests
-
-  if !flag(test-doctests)
-    buildable: False
-  else
-    build-depends:
-      base,
-      comonad,
-      doctest >= 0.11.1 && < 0.17
diff --git a/examples/History.hs b/examples/History.hs
--- a/examples/History.hs
+++ b/examples/History.hs
@@ -52,7 +52,7 @@
 ini dx = extract dx `fby` extend ini dx
 
 fibo :: Num b => History a -> b
-fibo d = wfix $ d $> fby 0 . extend (\dfibo -> extract dfibo + fby 1 dfibo) 
+fibo d = wfix $ d $> fby 0 . extend (\dfibo -> extract dfibo + fby 1 dfibo)
 
 fibo' :: Num b => History a -> b
 fibo' d = fst $ wfix $ d $> fby (0, 1) . fmap (\(x, x') -> (x',x+x'))
diff --git a/src/Control/Comonad.hs b/src/Control/Comonad.hs
--- a/src/Control/Comonad.hs
+++ b/src/Control/Comonad.hs
@@ -1,12 +1,8 @@
 {-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 707
-{-# LANGUAGE DeriveDataTypeable, StandaloneDeriving, Safe, DefaultSignatures #-}
-#elif __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Trustworthy, DefaultSignatures #-}
-#endif
-#if __GLASGOW_HASKELL__ >= 706
+{-# LANGUAGE DefaultSignatures #-}
+{-# LANGUAGE Safe #-}
+{-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE PolyKinds #-}
-#endif
  -----------------------------------------------------------------------------
 -- |
 -- Module      :  Control.Comonad
@@ -49,11 +45,6 @@
 import Control.Arrow
 import Control.Category
 import Control.Monad (ap)
-#if MIN_VERSION_base(4,7,0)
--- Control.Monad.Instances is empty
-#else
-import Control.Monad.Instances
-#endif
 import Control.Monad.Trans.Identity
 import Data.Functor.Identity
 import qualified Data.Functor.Sum as FSum
@@ -62,7 +53,6 @@
 import Data.Tagged
 import Prelude hiding (id, (.))
 import Control.Monad.Fix
-import Data.Typeable
 
 #ifdef MIN_VERSION_containers
 import Data.Tree
@@ -146,9 +136,7 @@
   extend :: (w a -> b) -> w a -> w b
   extend f = fmap f . duplicate
 
-#if __GLASGOW_HASKELL__ >= 708
   {-# MINIMAL extract, (duplicate | extend) #-}
-#endif
 
 
 instance Comonad ((,)e) where
@@ -157,7 +145,6 @@
   extract = snd
   {-# INLINE extract #-}
 
-#if MIN_VERSION_semigroups(0,16,2)
 instance Comonad (Arg e) where
   duplicate w@(Arg a _) = Arg a w
   {-# INLINE duplicate #-}
@@ -165,7 +152,6 @@
   {-# INLINE extend #-}
   extract (Arg _ b) = b
   {-# INLINE extract #-}
-#endif
 
 instance Monoid m => Comonad ((->)m) where
   duplicate f m = f . mappend m
@@ -179,14 +165,13 @@
   extract = runIdentity
   {-# INLINE extract #-}
 
-#if __GLASGOW_HASKELL__ >= 706
 -- $
 -- The variable `s` can have any kind.
 -- For example, here it has kind `Bool`:
 -- >>> :set -XDataKinds
+-- >>> import Data.Tagged
 -- >>> extract (Tagged 42 :: Tagged 'True Integer)
 -- 42
-#endif
 instance Comonad (Tagged s) where
   duplicate = Tagged
   {-# INLINE duplicate #-}
@@ -206,7 +191,8 @@
 #endif
 
 instance Comonad NonEmpty where
-  extend f w@ ~(_ :| aas) = f w :| case aas of
+  extend f w@(~(_ :| aas)) =
+    f w :| case aas of
       []     -> []
       (a:as) -> toList (extend f (a :| as))
   extract ~(a :| _) = a
@@ -256,10 +242,8 @@
 
 class Comonad w => ComonadApply w where
   (<@>) :: w (a -> b) -> w a -> w b
-#if __GLASGOW_HASKELL__ >= 702
   default (<@>) :: Applicative w => w (a -> b) -> w a -> w b
   (<@>) = (<*>)
-#endif
 
   (@>) :: w a -> w b -> w b
   a @> b = const id <$> a <@> b
@@ -298,8 +282,8 @@
 -- | A suitable default definition for 'fmap' for a 'Comonad'.
 -- Promotes a function to a comonad.
 --
--- You can only safely use to define 'fmap' if your 'Comonad'
--- defined 'extend', not just 'duplicate', since defining
+-- You can only safely use 'liftW' to define 'fmap' if your 'Comonad'
+-- defines 'extend', not just 'duplicate', since defining
 -- 'extend' in terms of duplicate uses 'fmap'!
 --
 -- @
@@ -362,25 +346,7 @@
 
 -- | The 'Cokleisli' 'Arrow's of a given 'Comonad'
 newtype Cokleisli w a b = Cokleisli { runCokleisli :: w a -> b }
-#if __GLASGOW_HASKELL__ >= 707
-  deriving Typeable
-#else
-#ifdef __GLASGOW_HASKELL__
-instance Typeable1 w => Typeable2 (Cokleisli w) where
-  typeOf2 twab = mkTyConApp cokleisliTyCon [typeOf1 (wa twab)]
-        where wa :: Cokleisli w a b -> w a
-              wa = undefined
-#endif
 
-cokleisliTyCon :: TyCon
-#if MIN_VERSION_base(4,4,0)
-cokleisliTyCon = mkTyCon3 "comonad" "Control.Comonad" "Cokleisli"
-#else
-cokleisliTyCon = mkTyCon "Control.Comonad.Cokleisli"
-#endif
-{-# NOINLINE cokleisliTyCon #-}
-#endif
-
 instance Comonad w => Category (Cokleisli w) where
   id = Cokleisli extract
   Cokleisli f . Cokleisli g = Cokleisli (f =<= g)
@@ -412,13 +378,3 @@
 instance Monad (Cokleisli w a) where
   return = pure
   Cokleisli k >>= f = Cokleisli $ \w -> runCokleisli (f (k w)) w
-
-#if !(MIN_VERSION_base(4,7,0))
-
-infixl 4 $>
-
--- | Replace the contents of a functor uniformly with a constant value.
-($>) :: Functor f => f a -> b -> f b
-($>) = flip (<$)
-
-#endif
diff --git a/src/Control/Comonad/Env.hs b/src/Control/Comonad/Env.hs
--- a/src/Control/Comonad/Env.hs
+++ b/src/Control/Comonad/Env.hs
@@ -1,9 +1,4 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 704
 {-# LANGUAGE Safe #-}
-#elif __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Trustworthy #-}
-#endif
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Control.Comonad.Env
diff --git a/src/Control/Comonad/Env/Class.hs b/src/Control/Comonad/Env/Class.hs
--- a/src/Control/Comonad/Env/Class.hs
+++ b/src/Control/Comonad/Env/Class.hs
@@ -2,12 +2,7 @@
 {-# LANGUAGE FunctionalDependencies #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE UndecidableInstances #-}
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 704
 {-# LANGUAGE Safe #-}
-#elif __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Trustworthy #-}
-#endif
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Control.Comonad.Env.Class
@@ -44,10 +39,8 @@
 instance ComonadEnv e ((,)e) where
   ask = fst
 
-#if MIN_VERSION_semigroups(0,16,2)
 instance ComonadEnv e (Arg e) where
   ask (Arg e _) = e
-#endif
 
 lowerAsk :: (ComonadEnv e w, ComonadTrans t) => t w a -> e
 lowerAsk = ask . lower
diff --git a/src/Control/Comonad/Hoist/Class.hs b/src/Control/Comonad/Hoist/Class.hs
--- a/src/Control/Comonad/Hoist/Class.hs
+++ b/src/Control/Comonad/Hoist/Class.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE Safe #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Control.Comonad.Hoist.Class
diff --git a/src/Control/Comonad/Identity.hs b/src/Control/Comonad/Identity.hs
--- a/src/Control/Comonad/Identity.hs
+++ b/src/Control/Comonad/Identity.hs
@@ -1,9 +1,4 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 704
 {-# LANGUAGE Safe #-}
-#elif __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Trustworthy #-}
-#endif
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Control.Comonad.Identity
diff --git a/src/Control/Comonad/Store.hs b/src/Control/Comonad/Store.hs
--- a/src/Control/Comonad/Store.hs
+++ b/src/Control/Comonad/Store.hs
@@ -1,9 +1,4 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 704
 {-# LANGUAGE Safe #-}
-#elif __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Trustworthy #-}
-#endif
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Control.Comonad.Store
diff --git a/src/Control/Comonad/Store/Class.hs b/src/Control/Comonad/Store/Class.hs
--- a/src/Control/Comonad/Store/Class.hs
+++ b/src/Control/Comonad/Store/Class.hs
@@ -1,13 +1,8 @@
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE FunctionalDependencies #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE UndecidableInstances #-}
-#if __GLASGOW_HASKELL__ >= 704
 {-# LANGUAGE Safe #-}
-#elif __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Trustworthy #-}
-#endif
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Control.Comonad.Store.Class
@@ -30,9 +25,6 @@
 import qualified Control.Comonad.Trans.Store as Store
 import Control.Comonad.Trans.Traced
 import Control.Comonad.Trans.Identity
-#if __GLASGOW_HASKELL__ < 710
-import Data.Semigroup
-#endif
 
 class Comonad w => ComonadStore s w | w -> s where
   pos :: w a -> s
diff --git a/src/Control/Comonad/Traced.hs b/src/Control/Comonad/Traced.hs
--- a/src/Control/Comonad/Traced.hs
+++ b/src/Control/Comonad/Traced.hs
@@ -1,9 +1,4 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 704
 {-# LANGUAGE Safe #-}
-#elif __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Trustworthy #-}
-#endif
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Control.Comonad.Traced
diff --git a/src/Control/Comonad/Traced/Class.hs b/src/Control/Comonad/Traced/Class.hs
--- a/src/Control/Comonad/Traced/Class.hs
+++ b/src/Control/Comonad/Traced/Class.hs
@@ -1,13 +1,8 @@
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE FunctionalDependencies #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE UndecidableInstances #-}
-#if __GLASGOW_HASKELL__ >= 704
 {-# LANGUAGE Safe #-}
-#elif __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Trustworthy #-}
-#endif
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Control.Comonad.Traced.Class
@@ -29,9 +24,6 @@
 import Control.Comonad.Trans.Store
 import qualified Control.Comonad.Trans.Traced as Traced
 import Control.Comonad.Trans.Identity
-#if __GLASGOW_HASKELL__ < 710
-import Data.Semigroup
-#endif
 
 class Comonad w => ComonadTraced m w | w -> m where
   trace :: m -> w a -> a
diff --git a/src/Control/Comonad/Trans/Class.hs b/src/Control/Comonad/Trans/Class.hs
--- a/src/Control/Comonad/Trans/Class.hs
+++ b/src/Control/Comonad/Trans/Class.hs
@@ -1,9 +1,4 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 704
 {-# LANGUAGE Safe #-}
-#elif __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Trustworthy #-}
-#endif
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Control.Comonad.Trans.Class
diff --git a/src/Control/Comonad/Trans/Env.hs b/src/Control/Comonad/Trans/Env.hs
--- a/src/Control/Comonad/Trans/Env.hs
+++ b/src/Control/Comonad/Trans/Env.hs
@@ -1,13 +1,7 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE FlexibleContexts #-}
-#if __GLASGOW_HASKELL__ >= 707
-{-# LANGUAGE StandaloneDeriving, DeriveDataTypeable, Safe #-}
-#elif __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Trustworthy #-}
-#endif
-#ifndef MIN_VERSION_base
-#define MIN_VERSION_base(x,y,z) 1
-#endif
+{-# LANGUAGE Safe #-}
+{-# LANGUAGE StandaloneDeriving #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Control.Comonad.Trans.Env
@@ -62,56 +56,26 @@
   , local
   ) where
 
-#if !(MIN_VERSION_base(4,8,0))
-import Control.Applicative
-#endif
 import Control.Comonad
 import Control.Comonad.Hoist.Class
 import Control.Comonad.Trans.Class
-#if __GLASGOW_HASKELL__ < 710
-import Data.Foldable
-import Data.Traversable
-#endif
+import Data.Data
 import Data.Functor.Identity
 #if !(MIN_VERSION_base(4,11,0))
 import Data.Semigroup
 #endif
 
-#ifdef __GLASGOW_HASKELL__
-#if __GLASGOW_HASKELL__ >= 707
-#define Typeable1 Typeable
-#endif
-import Data.Data
-
-#if __GLASGOW_HASKELL__ >= 707
-deriving instance Typeable EnvT
-#else
-instance (Typeable s, Typeable1 w) => Typeable1 (EnvT s w) where
-  typeOf1 dswa = mkTyConApp envTTyCon [typeOf (s dswa), typeOf1 (w dswa)]
-    where
-      s :: EnvT s w a -> s
-      s = undefined
-      w :: EnvT s w a -> w a
-      w = undefined
-
-envTTyCon :: TyCon
-#if __GLASGOW_HASKELL__ < 704
-envTTyCon = mkTyCon "Control.Comonad.Trans.Env.EnvT"
-#else
-envTTyCon = mkTyCon3 "comonad-transformers" "Control.Comonad.Trans.Env" "EnvT"
-#endif
-{-# NOINLINE envTTyCon #-}
-
+#ifdef __MHS__
+import Data.Foldable
+import Data.Traversable
 #endif
 
-#if __GLASGOW_HASKELL__ < 707
-instance (Typeable s, Typeable1 w, Typeable a) => Typeable (EnvT s w a) where
-  typeOf = typeOfDefault
-#endif
+-- $setup
+-- >>> import Control.Comonad
 
 instance
   ( Data e
-  , Typeable1 w, Data (w a)
+  , Typeable w, Data (w a)
   , Data a
   ) => Data (EnvT e w a) where
     gfoldl f z (EnvT e wa) = z EnvT `f` e `f` wa
@@ -129,8 +93,6 @@
 envTDataType :: DataType
 envTDataType = mkDataType "Control.Comonad.Trans.Env.EnvT" [envTConstr]
 {-# NOINLINE envTDataType #-}
-
-#endif
 
 type Env e = EnvT e Identity
 data EnvT e w a = EnvT e (w a)
diff --git a/src/Control/Comonad/Trans/Identity.hs b/src/Control/Comonad/Trans/Identity.hs
--- a/src/Control/Comonad/Trans/Identity.hs
+++ b/src/Control/Comonad/Trans/Identity.hs
@@ -1,9 +1,4 @@
-{-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 704
 {-# LANGUAGE Safe #-}
-#elif __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Trustworthy #-}
-#endif
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Control.Comonad.Trans.Identity
diff --git a/src/Control/Comonad/Trans/Store.hs b/src/Control/Comonad/Trans/Store.hs
--- a/src/Control/Comonad/Trans/Store.hs
+++ b/src/Control/Comonad/Trans/Store.hs
@@ -1,9 +1,6 @@
 {-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 707
-{-# LANGUAGE StandaloneDeriving, DeriveDataTypeable, Safe #-}
-#elif __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Trustworthy #-}
-#endif
+{-# LANGUAGE Safe #-}
+{-# LANGUAGE StandaloneDeriving #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Control.Comonad.Trans.Store
@@ -75,9 +72,6 @@
   , experiment
   ) where
 
-#if __GLASGOW_HASKELL__ < 710
-import Control.Applicative
-#endif
 import Control.Comonad
 import Control.Comonad.Hoist.Class
 import Control.Comonad.Trans.Class
@@ -86,36 +80,9 @@
 import Data.Semigroup
 #endif
 
-#ifdef __GLASGOW_HASKELL__
-import Data.Typeable
-
 -- $setup
+-- >>> import Control.Comonad
 -- >>> import Data.Tuple (swap)
-
-#if __GLASGOW_HASKELL__ >= 707
-deriving instance Typeable StoreT
-#else
-instance (Typeable s, Typeable1 w) => Typeable1 (StoreT s w) where
-  typeOf1 dswa = mkTyConApp storeTTyCon [typeOf (s dswa), typeOf1 (w dswa)]
-    where
-      s :: StoreT s w a -> s
-      s = undefined
-      w :: StoreT s w a -> w a
-      w = undefined
-
-instance (Typeable s, Typeable1 w, Typeable a) => Typeable (StoreT s w a) where
-  typeOf = typeOfDefault
-
-storeTTyCon :: TyCon
-#if __GLASGOW_HASKELL__ < 704
-storeTTyCon = mkTyCon "Control.Comonad.Trans.Store.StoreT"
-#else
-storeTTyCon = mkTyCon3 "comonad-transformers" "Control.Comonad.Trans.Store" "StoreT"
-#endif
-{-# NOINLINE storeTTyCon #-}
-#endif
-
-#endif
 
 type Store s = StoreT s Identity
 
diff --git a/src/Control/Comonad/Trans/Traced.hs b/src/Control/Comonad/Trans/Traced.hs
--- a/src/Control/Comonad/Trans/Traced.hs
+++ b/src/Control/Comonad/Trans/Traced.hs
@@ -1,8 +1,8 @@
 {-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 707
-{-# LANGUAGE StandaloneDeriving, DeriveDataTypeable, Safe #-}
-#elif __GLASGOW_HASKELL__ >= 702
-{-# LANGUAGE Trustworthy #-}
+{-# LANGUAGE Safe #-}
+{-# LANGUAGE StandaloneDeriving #-}
+#ifdef MIN_VERSION_indexed_traversable
+{-# LANGUAGE MultiParamTypeClasses, UndecidableInstances #-}
 #endif
 -----------------------------------------------------------------------------
 -- |
@@ -36,14 +36,6 @@
   , censor
   ) where
 
-#if __GLASGOW_HASKELL__ < 710
-import Control.Applicative
-#endif
-
-#if __GLASGOW_HASKELL__ < 707
-import Control.Monad.Instances ()
-#endif
-
 import Control.Monad (ap)
 import Control.Comonad
 import Control.Comonad.Hoist.Class
@@ -53,13 +45,11 @@
 import Data.Distributive
 #endif
 
-import Data.Functor.Identity
-
-#if __GLASGOW_HASKELL__ < 710
-import Data.Semigroup
+#ifdef MIN_VERSION_indexed_traversable
+import Data.Functor.WithIndex
 #endif
 
-import Data.Typeable
+import Data.Functor.Identity
 
 
 type Traced m = TracedT m Identity
@@ -97,6 +87,12 @@
   distribute = TracedT . fmap (\tma m -> fmap ($ m) tma) . collect runTracedT
 #endif
 
+#ifdef MIN_VERSION_indexed_traversable
+instance FunctorWithIndex i w => FunctorWithIndex (s, i) (TracedT s w) where
+  imap f (TracedT w) = TracedT $ imap (\k' g k -> f (k, k') (g k)) w
+  {-# INLINE imap #-}
+#endif
+
 trace :: Comonad w => m -> TracedT m w a -> a
 trace m (TracedT wf) = extract wf m
 
@@ -108,28 +104,3 @@
 
 censor :: Functor w => (m -> m) -> TracedT m w a -> TracedT m w a
 censor g = TracedT . fmap (. g) . runTracedT
-
-#ifdef __GLASGOW_HASKELL__
-
-#if __GLASGOW_HASKELL__ >= 707
-deriving instance Typeable TracedT
-#else
-instance (Typeable s, Typeable1 w) => Typeable1 (TracedT s w) where
-  typeOf1 dswa = mkTyConApp tracedTTyCon [typeOf (s dswa), typeOf1 (w dswa)]
-    where
-      s :: TracedT s w a -> s
-      s = undefined
-      w :: TracedT s w a -> w a
-      w = undefined
-
-tracedTTyCon :: TyCon
-#if __GLASGOW_HASKELL__ < 704
-tracedTTyCon = mkTyCon "Control.Comonad.Trans.Traced.TracedT"
-#else
-tracedTTyCon = mkTyCon3 "comonad-transformers" "Control.Comonad.Trans.Traced" "TracedT"
-#endif
-{-# NOINLINE tracedTTyCon #-}
-
-#endif
-
-#endif
diff --git a/src/Data/Functor/Composition.hs b/src/Data/Functor/Composition.hs
--- a/src/Data/Functor/Composition.hs
+++ b/src/Data/Functor/Composition.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE Safe #-}
 module Data.Functor.Composition
   ( Composition(..) ) where
 
diff --git a/tests/doctests.hs b/tests/doctests.hs
deleted file mode 100644
--- a/tests/doctests.hs
+++ /dev/null
@@ -1,25 +0,0 @@
------------------------------------------------------------------------------
--- |
--- Module      :  Main (doctests)
--- Copyright   :  (C) 2012-14 Edward Kmett
--- License     :  BSD-style (see the file LICENSE)
--- Maintainer  :  Edward Kmett <ekmett@gmail.com>
--- Stability   :  provisional
--- Portability :  portable
---
--- This module provides doctests for a project based on the actual versions
--- of the packages it was built with. It requires a corresponding Setup.lhs
--- to be added to the project
------------------------------------------------------------------------------
-module Main where
-
-import Build_doctests (flags, pkgs, module_sources)
-import Data.Foldable (traverse_)
-import Test.DocTest
-
-main :: IO ()
-main = do
-    traverse_ putStrLn args
-    doctest args
-  where
-    args = flags ++ pkgs ++ module_sources