diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,11 @@
+0.2.5 [2021.02.17]
+------------------
+* Allow building with `lens-5.*`.
+* 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.
+
 0.2.4 [2019.09.13]
 ------------------
 * Remove the use of `cpp-options: -traditional`. This should be unnecessary
diff --git a/README.markdown b/README.markdown
--- a/README.markdown
+++ b/README.markdown
@@ -1,7 +1,7 @@
 lens-action
 ===========
 
-[![Hackage](https://img.shields.io/hackage/v/lens-action.svg)](https://hackage.haskell.org/package/lens-action) [![Build Status](https://secure.travis-ci.org/ekmett/lens-action.png?branch=master)](http://travis-ci.org/ekmett/lens-action)
+[![Hackage](https://img.shields.io/hackage/v/lens-action.svg)](https://hackage.haskell.org/package/lens-action) [![Build Status](https://github.com/ekmett/lens-action/workflows/Haskell-CI/badge.svg)](https://github.com/ekmett/lens-action/actions?query=workflow%3AHaskell-CI)
 
 This package contains combinators and types for working with monadic getters and folds as split off from the original `lens` package.
 
diff --git a/Setup.lhs b/Setup.lhs
--- a/Setup.lhs
+++ b/Setup.lhs
@@ -1,34 +1,7 @@
-\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
-
-main :: IO ()
-main = defaultMain
+#!/usr/bin/runhaskell
+> module Main (main) where
 
-#endif
+> import Distribution.Simple
 
-\end{code}
+> main :: IO ()
+> main = defaultMain
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/lens-action.cabal b/lens-action.cabal
--- a/lens-action.cabal
+++ b/lens-action.cabal
@@ -1,8 +1,8 @@
 name:          lens-action
 category:      Data, Lenses, Generics
-version:       0.2.4
+version:       0.2.5
 license:       BSD3
-cabal-version: >= 1.8
+cabal-version: >= 1.10
 license-file:  LICENSE
 author:        Edward A. Kmett
 maintainer:    Edward A. Kmett <ekmett@gmail.com>
@@ -10,7 +10,7 @@
 homepage:      http://github.com/ekmett/lens-action/
 bug-reports:   http://github.com/ekmett/lens-action/issues
 copyright:     Copyright (C) 2012-2014 Edward A. Kmett
-build-type:    Custom
+build-type:    Simple
 -- build-tools:   cpphs
 tested-with:   GHC == 7.4.2
              , GHC == 7.6.3
@@ -20,7 +20,8 @@
              , GHC == 8.2.2
              , GHC == 8.4.4
              , GHC == 8.6.5
-             , GHC == 8.8.1
+             , GHC == 8.8.3
+             , GHC == 8.10.1
 synopsis:      Monadic Getters and Folds
 description:
   This package contains combinators and types for working with
@@ -32,35 +33,26 @@
   .gitignore
   CHANGELOG.markdown
   README.markdown
-  Warning.hs
 
-custom-setup
-  setup-depends:
-    base          >= 4.3 && <5,
-    Cabal         >= 1.10,
-    cabal-doctest >= 1 && <1.1
-
 source-repository head
   type: git
   location: git://github.com/ekmett/lens-action.git
 
--- You can disable the doctests test suite with -f-test-doctests
-flag test-doctests
-  default: True
-  manual: True
-
 library
   build-depends:
-    lens                      >= 4.7      && < 5,
+    lens                      >= 4.7      && < 6,
     base                      >= 4.5      && < 5,
     comonad                   >= 4        && < 6,
     contravariant             >= 1.2.1    && < 2,
     profunctors               >= 4        && < 6,
     mtl                       >= 2.0.1    && < 2.3,
-    semigroups                >= 0.8.4    && < 1,
     semigroupoids             >= 4        && < 6,
     transformers              >= 0.2      && < 0.6
 
+  if impl(ghc < 8.0)
+    build-depends:
+      semigroups              >= 0.8.4    && < 1
+
   exposed-modules:
     Control.Lens.Action
     Control.Lens.Action.Internal
@@ -69,20 +61,4 @@
 
   ghc-options: -Wall -fwarn-tabs -O2 -fdicts-cheap -funbox-strict-fields -fmax-simplifier-iterations=10
   hs-source-dirs: src
-
--- Verify the results of the examples
-test-suite doctests
-  type:           exitcode-stdio-1.0
-  main-is:        doctests.hs
-  ghc-options:    -Wall -threaded
-  hs-source-dirs: tests
-
-  if !flag(test-doctests)
-    buildable: False
-  else
-    build-depends:
-      base,
-      doctest        >= 0.9.1,
-      filepath,
-      directory,
-      lens-action
+  default-language: Haskell2010
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
