diff --git a/.travis.yml b/.travis.yml
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,8 @@
 # This Travis job script has been generated by a script via
 #
-#   runghc make_travis_yml_2.hs '-o' '.travis.yml' '--irc-channel=irc.freenode.org#haskell-lens' '--no-no-tests-no-bench' '--no-installed' 'cabal.project'
+#   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' '--allow-failure=7.0.4' '--allow-failure=7.2.2' '--doctest' 'cabal.project'
 #
-# For more information, see https://github.com/hvr/multi-ghc-travis
+# For more information, see https://github.com/haskell-CI/haskell-ci
 #
 language: c
 sudo: false
@@ -34,58 +34,57 @@
 
   - rm -rfv $HOME/.cabal/packages/head.hackage
 
-addons:
-  apt:
-    packages: &apt_packages
-      - ghc-ppa-tools
-      - hlint
-
 matrix:
   include:
-    - compiler: "ghc-7.0.4"
+    - compiler: "ghc-8.6.3"
     # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-7.0.4], sources: [hvr-ghc]}}
-    - compiler: "ghc-7.2.2"
+      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,ghc-8.6.3], sources: [hvr-ghc]}}
+    - compiler: "ghc-8.4.4"
     # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-7.2.2], sources: [hvr-ghc]}}
-    - compiler: "ghc-7.4.2"
+      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,ghc-8.4.4], sources: [hvr-ghc]}}
+    - compiler: "ghc-8.2.2"
     # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-7.4.2], sources: [hvr-ghc]}}
-    - compiler: "ghc-7.6.3"
+      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,ghc-8.2.2], sources: [hvr-ghc]}}
+    - compiler: "ghc-8.0.2"
     # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-7.6.3], sources: [hvr-ghc]}}
+      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,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-2.4,ghc-7.10.3], sources: [hvr-ghc]}}
     - compiler: "ghc-7.8.4"
     # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-7.8.4], sources: [hvr-ghc]}}
-    - compiler: "ghc-7.10.3"
+      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,ghc-7.8.4], sources: [hvr-ghc]}}
+    - compiler: "ghc-7.6.3"
     # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-7.10.3], sources: [hvr-ghc]}}
-    - compiler: "ghc-8.0.2"
+      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,ghc-7.6.3], sources: [hvr-ghc]}}
+    - compiler: "ghc-7.4.2"
     # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-8.0.2], sources: [hvr-ghc]}}
-    - compiler: "ghc-8.2.2"
+      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,ghc-7.4.2], sources: [hvr-ghc]}}
+    - compiler: "ghc-7.2.2"
     # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [*apt_packages,cabal-install-2.0,ghc-8.2.2], sources: [hvr-ghc]}}
-    - compiler: "ghc-8.4.1"
-      env: GHCHEAD=true
-      addons: {apt: {packages: [*apt_packages,cabal-install-head,ghc-8.4.1], sources: [hvr-ghc]}}
+      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,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-2.4,ghc-7.0.4], sources: [hvr-ghc]}}
     - compiler: "ghc-head"
       env: GHCHEAD=true
-      addons: {apt: {packages: [*apt_packages,cabal-install-head,ghc-head], sources: [hvr-ghc]}}
+      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-8.4.1"
-    - compiler: "ghc-head"
 
 before_install:
   - HC=${CC}
   - HCPKG=${HC/ghc/ghc-pkg}
   - unset CC
+  - export HLINTVER=2.0.9
+  - mkdir ~/.hlint
+  - curl -L https://github.com/ndmitchell/hlint/releases/download/v$HLINTVER/hlint-$HLINTVER-x86_64-linux.tar.gz | tar -xz --strip-components=1 -C ~/.hlint
   - ROOTDIR=$(pwd)
   - mkdir -p $HOME/.local/bin
-  - "PATH=/opt/ghc/bin:/opt/ghc-ppa-tools/bin:$HOME/local/bin:$PATH"
+  - "PATH=~/.hlint:/opt/ghc/bin:/opt/ghc-ppa-tools/bin:$HOME/local/bin:$PATH"
   - HCNUMVER=$(( $(${HC} --numeric-version|sed -E 's/([0-9]+)\.([0-9]+)\.([0-9]+).*/\1 * 10000 + \2 * 100 + \3/') ))
   - echo $HCNUMVER
 
@@ -95,7 +94,8 @@
   - BENCH=${BENCH---enable-benchmarks}
   - TEST=${TEST---enable-tests}
   - HADDOCK=${HADDOCK-true}
-  - INSTALLED=${INSTALLED-true}
+  - UNCONSTRAINED=${UNCONSTRAINED-true}
+  - NOINSTALLEDCONSTRAINTS=${NOINSTALLEDCONSTRAINTS-false}
   - GHCHEAD=${GHCHEAD-false}
   - travis_retry cabal update -v
   - "sed -i.bak 's/^jobs:/-- jobs:/' ${HOME}/.cabal/config"
@@ -103,7 +103,8 @@
   # Overlay Hackage Package Index for GHC HEAD: https://github.com/hvr/head.hackage
   - |
     if $GHCHEAD; then
-      sed -i.bak 's/-- allow-newer:.*/allow-newer: *:base, *:template-haskell, *:ghc, *:Cabal/' ${HOME}/.cabal/config
+      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
@@ -113,44 +114,56 @@
       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*--' ${HOME}/.cabal/config | grep -Ev '^\s*$'
+  - (cd /tmp && echo '' | cabal new-repl -w ${HC} --build-dep fail)
+  - if [ $HCNUMVER -ge 80000 ]; then cabal new-install -w ${HC} -j2 --symlink-bindir=$HOME/.local/bin doctest --constraint='doctest ==0.16.*'; fi
   - "printf 'packages: \".\"\\n' > cabal.project"
-  - cat cabal.project
+  - "printf 'write-ghc-environment-files: always\\n' >> cabal.project"
+  - touch cabal.project.local
+  - "if ! $NOINSTALLEDCONSTRAINTS; then for pkg in $($HCPKG list --simple-output); do echo $pkg  | grep -vw -- heaps | sed 's/^/constraints: /' | sed 's/-[^-]*$/ installed/' >> cabal.project.local; done; fi"
+  - cat cabal.project || true
+  - cat cabal.project.local || true
   - if [ -f "./configure.ac" ]; then
       (cd "." && autoreconf -i);
     fi
   - rm -f cabal.project.freeze
   - cabal new-build -w ${HC} ${TEST} ${BENCH} --project-file="cabal.project" --dep -j2 all
-  - rm -rf "."/.ghc.environment.* "."/dist
+  - rm -rf .ghc.environment.* "."/dist
   - DISTDIR=$(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)
-  - mv "."/dist/heaps-*.tar.gz ${DISTDIR}/
+  - cabal new-sdist all
+  - mv dist-newstyle/sdist/*.tar.gz ${DISTDIR}/
   - cd ${DISTDIR} || false
   - find . -maxdepth 1 -name '*.tar.gz' -exec tar -xvf '{}' \;
   - "printf 'packages: heaps-*/*.cabal\\n' > cabal.project"
-  - cat cabal.project
-
+  - "printf 'write-ghc-environment-files: always\\n' >> cabal.project"
+  - touch cabal.project.local
+  - "if ! $NOINSTALLEDCONSTRAINTS; then for pkg in $($HCPKG list --simple-output); do echo $pkg  | grep -vw -- heaps | sed 's/^/constraints: /' | sed 's/-[^-]*$/ 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
 
+  # doctest
+  - if [ $HCNUMVER -ge 80000 ]; then (cd heaps-* && doctest  src); fi
+
   # cabal check
   - (cd heaps-* && cabal check)
 
   # haddock
-  - rm -rf ./dist-newstyle
   - if $HADDOCK; then cabal new-haddock -w ${HC} ${TEST} ${BENCH} all; else echo "Skipping haddock generation";fi
 
   # hlint
-  - (cd heaps-* && hlint src --cpp-define=HLINT)
+  - (cd heaps-* && hlint src --cpp-ansi --cpp-define=HLINT)
 
-# REGENDATA ["-o",".travis.yml","--irc-channel=irc.freenode.org#haskell-lens","--no-no-tests-no-bench","--no-installed","cabal.project"]
+# REGENDATA ["-o",".travis.yml","--ghc-head","--irc-channel=irc.freenode.org#haskell-lens","--no-no-tests-no-bench","--no-unconstrained","--allow-failure=7.0.4","--allow-failure=7.2.2","--doctest","cabal.project"]
 # EOF
diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,10 @@
+0.3.6.1
+-------
+* Change to `build-type: Simple`, and drop the `doctests` test suite. This was
+  done in an effort to make `heaps`' dependency footprint as minimal as
+  possible, since `heaps` is used to bootstrap `shake`.
+* Fix the Haddocks for `span`.
+
 0.3.6 [2018.01.18]
 ------------------
 * Add `Semigroup` instance for `Heap`.
diff --git a/HLint.hs b/HLint.hs
--- a/HLint.hs
+++ b/HLint.hs
@@ -1,1 +1,2 @@
 ignore "Use infix"
+ignore "Use fmap"
diff --git a/Setup.lhs b/Setup.lhs
deleted file mode 100644
--- a/Setup.lhs
+++ /dev/null
@@ -1,34 +0,0 @@
-\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
-
-#endif
-
-\end{code}
diff --git a/heaps.cabal b/heaps.cabal
--- a/heaps.cabal
+++ b/heaps.cabal
@@ -1,5 +1,5 @@
 name:           heaps
-version:        0.3.6
+version:        0.3.6.1
 license:        BSD3
 license-file:   LICENSE
 author:         Edward A. Kmett
@@ -19,8 +19,9 @@
               , GHC == 7.10.3
               , GHC == 8.0.2
               , GHC == 8.2.2
-              , GHC == 8.4.1
-build-type:     Custom
+              , GHC == 8.4.4
+              , GHC == 8.6.3
+build-type:     Simple
 cabal-version:  >=1.8
 extra-source-files:
   HLint.hs
@@ -30,12 +31,6 @@
   CHANGELOG.markdown
   README.markdown
 
-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/heaps.git
@@ -46,16 +41,3 @@
     base >= 4 && < 6
   hs-source-dirs: src
   ghc-options: -O2
-
--- Verify the results of the examples
-test-suite doctests
-  type:    exitcode-stdio-1.0
-  main-is: doctests.hs
-  build-depends:
-    base,
-    directory >= 1.0 && < 1.4,
-    doctest >= 0.9 && < 0.14,
-    filepath,
-    heaps
-  ghc-options: -Wall
-  hs-source-dirs: tests
diff --git a/src/Data/Heap.hs b/src/Data/Heap.hs
--- a/src/Data/Heap.hs
+++ b/src/Data/Heap.hs
@@ -545,7 +545,7 @@
 -- >>> span (\x -> x `mod` 4 == 0) (fromList [4,8,12,14,16])
 -- (fromList [4,8,12],fromList [14,16])
 --
--- 'span' @p xs@ is equivalent to @('takeWhile' p xs, 'dropWhile p xs)@
+-- 'span' @p xs@ is equivalent to @('takeWhile' p xs, 'dropWhile' p xs)@
 
 span :: (a -> Bool) -> Heap a -> (Heap a, Heap a)
 span = splitWithList . L.span
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
