diff --git a/.travis.yml b/.travis.yml
index a4157a3..99a6089 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,23 +1,21 @@
 # This Travis job script has been generated by a script via
 #
-#   haskell-ci 'selective.cabal' '--osx=8.6.4' '-o' '.travis.yml'
+#   haskell-ci 'selective.cabal' '--osx=8.6.5' '-o' '.travis.yml'
 #
 # For more information, see https://github.com/haskell-CI/haskell-ci
 #
-# version: 0.2.1
+# version: 0.3.20190429
 #
 language: c
 dist: xenial
-
 git:
-  submodules: false  # whether to recursively clone submodules
-
+  # whether to recursively clone submodules
+  submodules: false
 cache:
   directories:
     - $HOME/.cabal/packages
     - $HOME/.cabal/store
     - $HOME/.ghc-install
-
 before_cache:
   - rm -fv $CABALHOME/packages/hackage.haskell.org/build-reports.log
   # remove files that are regenerated by 'cabal update'
@@ -26,95 +24,143 @@ before_cache:
   - rm -fv $CABALHOME/packages/hackage.haskell.org/01-index.cache
   - rm -fv $CABALHOME/packages/hackage.haskell.org/01-index.tar
   - rm -fv $CABALHOME/packages/hackage.haskell.org/01-index.tar.idx
-
   - rm -rfv $CABALHOME/packages/head.hackage
-
 matrix:
   include:
-    - compiler: "ghc-8.6.4"
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,ghc-8.6.4], sources: [hvr-ghc]}}
-    - compiler: "ghc-8.4.3"
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,ghc-8.4.3], sources: [hvr-ghc]}}
-    - compiler: "ghc-8.2.2"
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,ghc-8.2.2], sources: [hvr-ghc]}}
-    - compiler: "ghc-8.0.2"
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,ghc-8.0.2], sources: [hvr-ghc]}}
-    - compiler: "ghc-8.6.4"
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,ghc-8.6.4], sources: [hvr-ghc]}}
+    - compiler: ghc-8.8.1
+      addons: {"apt":{"sources":["hvr-ghc"],"packages":["ghc-8.8.1","cabal-install-3.0"]}}
+      env: GHCHEAD=true
+    - compiler: ghc-8.6.5
+      addons: {"apt":{"sources":["hvr-ghc"],"packages":["ghc-8.6.5","cabal-install-2.4"]}}
+    - compiler: ghc-8.4.3
+      addons: {"apt":{"sources":["hvr-ghc"],"packages":["ghc-8.4.3","cabal-install-2.4"]}}
+    - compiler: ghc-8.2.2
+      addons: {"apt":{"sources":["hvr-ghc"],"packages":["ghc-8.2.2","cabal-install-2.4"]}}
+    - compiler: ghc-8.0.2
+      addons: {"apt":{"sources":["hvr-ghc"],"packages":["ghc-8.0.2","cabal-install-2.4"]}}
+    - compiler: ghc-8.6.5
+      addons: {"apt":{"sources":["hvr-ghc"],"packages":["ghc-8.6.5","cabal-install-2.4"]}}
       os: osx
-
+  allow_failures:
+    - compiler: ghc-8.8.1
 before_install:
-  - HC=/opt/ghc/bin/${CC}
-  - HCPKG=${HC/ghc/ghc-pkg}
+  - HC=$(echo "/opt/$CC/bin/ghc" | sed 's/-/\//')
+  - HCPKG="$HC-pkg"
   - unset CC
   - CABAL=/opt/ghc/bin/cabal
   - CABALHOME=$HOME/.cabal
   - export PATH="$CABALHOME/bin:$PATH"
-  - ROOTDIR=$(pwd)
+  - TOP=$(pwd)
   - if [ "$TRAVIS_OS_NAME" = "osx" ]; then brew update; brew upgrade python@3; curl https://haskell.futurice.com/haskell-on-macos.py | python3 - --make-dirs --install-dir=$HOME/.ghc-install --cabal-alias=head install cabal-install-head ${TRAVIS_COMPILER}; fi
   - if [ "$TRAVIS_OS_NAME" = "osx" ]; then HC=$HOME/.ghc-install/ghc/bin/$TRAVIS_COMPILER; HCPKG=${HC/ghc/ghc-pkg}; CABAL=$HOME/.ghc-install/ghc/bin/cabal; fi
   - HCNUMVER=$(( $(${HC} --numeric-version|sed -E 's/([0-9]+)\.([0-9]+)\.([0-9]+).*/\1 * 10000 + \2 * 100 + \3/') ))
   - echo $HCNUMVER
-
+  - CABAL="$CABAL -vnormal+nowrap+markoutput"
+  - set -o pipefail
+  - |
+    echo 'function blue(s) { printf "\033[0;34m" s "\033[0m " }'           >> .colorful.awk
+    echo 'BEGIN { state = "output"; }'                                     >> .colorful.awk
+    echo '/^-----BEGIN CABAL OUTPUT-----$/ { state = "cabal" }'            >> .colorful.awk
+    echo '/^-----END CABAL OUTPUT-----$/ { state = "output" }'             >> .colorful.awk
+    echo '!/^(-----BEGIN CABAL OUTPUT-----|-----END CABAL OUTPUT-----)/ {' >> .colorful.awk
+    echo '  if (state == "cabal") {'                                       >> .colorful.awk
+    echo '    print blue($0)'                                              >> .colorful.awk
+    echo '  } else {'                                                      >> .colorful.awk
+    echo '    print $0'                                                    >> .colorful.awk
+    echo '  }'                                                             >> .colorful.awk
+    echo '}'                                                               >> .colorful.awk
+  - cat .colorful.awk
+  - |
+    color_cabal_output () {
+      awk -f $TOP/.colorful.awk
+    }
+  - echo text | color_cabal_output
 install:
   - ${CABAL} --version
   - echo "$(${HC} --version) [$(${HC} --print-project-git-commit-id 2> /dev/null || echo '?')]"
   - TEST=--enable-tests
   - BENCH=--enable-benchmarks
   - GHCHEAD=${GHCHEAD-false}
-  - travis_retry ${CABAL} update -v
-  - sed -i.bak 's/^jobs:/-- jobs:/' $CABALHOME/config
-  - rm -fv cabal.project cabal.project.local
-  - grep -Ev -- '^\s*--' $CABALHOME/config | grep -Ev '^\s*$'
-  - rm -f cabal.project
+  - rm -f $CABALHOME/config
+  - |
+    echo "verbose: normal +nowrap +markoutput"          >> $CABALHOME/config
+    echo "remote-build-reporting: anonymous"            >> $CABALHOME/config
+    echo "remote-repo-cache: $CABALHOME/packages"       >> $CABALHOME/config
+    echo "logs-dir:          $CABALHOME/logs"           >> $CABALHOME/config
+    echo "world-file:        $CABALHOME/world"          >> $CABALHOME/config
+    echo "extra-prog-path:   $CABALHOME/bin"            >> $CABALHOME/config
+    echo "symlink-bindir:    $CABALHOME/bin"            >> $CABALHOME/config
+    echo "installdir:        $CABALHOME/bin"            >> $CABALHOME/config
+    echo "build-summary:     $CABALHOME/logs/build.log" >> $CABALHOME/config
+    echo "store-dir:         $CABALHOME/store"          >> $CABALHOME/config
+    echo "install-dirs user"                            >> $CABALHOME/config
+    echo "  prefix: $CABALHOME"                         >> $CABALHOME/config
+    echo "repository hackage.haskell.org"               >> $CABALHOME/config
+    echo "  url: http://hackage.haskell.org/"           >> $CABALHOME/config
+  - |
+    if $GHCHEAD; then
+    echo "allow-newer: $($HCPKG list --simple-output | sed -E 's/([a-zA-Z-]+)-[0-9.]+/*:\1/g')" >> $CABALHOME/config
+    
+    echo "repository head.hackage"                                                        >> $CABALHOME/config
+    echo "   url: http://head.hackage.haskell.org/"                                       >> $CABALHOME/config
+    echo "   secure: True"                                                                >> $CABALHOME/config
+    echo "   root-keys: 07c59cb65787dedfaef5bd5f987ceb5f7e5ebf88b904bbd4c5cbdeb2ff71b740" >> $CABALHOME/config
+    echo "              2e8555dde16ebd8df076f1a8ef13b8f14c66bad8eafefd7d9e37d0ed711821fb" >> $CABALHOME/config
+    echo "              8f79fd2389ab2967354407ec852cbe73f2e8635793ac446d09461ffb99527f6e" >> $CABALHOME/config
+    echo "   key-threshold: 3"                                                            >> $CABALHOME/config
+    fi
+  - cat $CABALHOME/config
+  - rm -fv cabal.project cabal.project.local cabal.project.freeze
+  - travis_retry ${CABAL} v2-update -v
+  # Generate cabal.project
+  - rm -rf cabal.project cabal.project.local cabal.project.freeze
   - touch cabal.project
-  - "printf 'packages: \".\"\\n' >> cabal.project"
-  - "printf 'write-ghc-environment-files: always\\n' >> cabal.project"
-  - touch cabal.project.local
-  - "for pkg in $($HCPKG list --simple-output); do echo $pkg | sed 's/-[^-]*$//' | grep -vE -- '^(selective)$' | sed 's/^/constraints: /' | sed 's/$/ installed/' >> cabal.project.local; done"
+  - |
+    echo 'packages: "."' >> cabal.project
+  - |
+    echo "write-ghc-environment-files: always" >> cabal.project
+  - "for pkg in $($HCPKG list --simple-output); do echo $pkg | sed 's/-[^-]*$//' | (grep -vE -- '^(selective)$' || true) | sed 's/^/constraints: /' | sed 's/$/ installed/' >> cabal.project.local; done"
   - 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-freeze -w ${HC} ${TEST} ${BENCH} --project-file="cabal.project" --dry
-  - "cat \"cabal.project.freeze\" | sed -E 's/^(constraints: *| *)//' | sed 's/any.//'"
-  - rm  "cabal.project.freeze"
-  - ${CABAL} new-build -w ${HC} ${TEST} ${BENCH} --project-file="cabal.project" --dep -j2 all
-  - ${CABAL} new-build -w ${HC} --disable-tests --disable-benchmarks --project-file="cabal.project" --dep -j2 all
-  - rm -rf .ghc.environment.* "."/dist
-  - DISTDIR=$(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.
+  - ${CABAL} v2-freeze -w ${HC} ${TEST} ${BENCH} | color_cabal_output
+  - "cat cabal.project.freeze | sed -E 's/^(constraints: *| *)//' | sed 's/any.//'"
+  - rm  cabal.project.freeze
+  - ${CABAL} v2-build -w ${HC} ${TEST} ${BENCH} --dep -j2 all | color_cabal_output
+  - ${CABAL} v2-build -w ${HC} --disable-tests --disable-benchmarks --dep -j2 all | color_cabal_output
 script:
-  # test that source-distributions can be generated
-  - ${CABAL} new-sdist all
+  - DISTDIR=$(mktemp -d /tmp/dist-test.XXXX)
+  # Packaging...
+  - ${CABAL} v2-sdist all | color_cabal_output
+  # Unpacking...
   - mv dist-newstyle/sdist/*.tar.gz ${DISTDIR}/
   - cd ${DISTDIR} || false
   - find . -maxdepth 1 -name '*.tar.gz' -exec tar -xvf '{}' \;
-  - rm -f cabal.project
+  # Generate cabal.project
+  - rm -rf cabal.project cabal.project.local cabal.project.freeze
   - touch cabal.project
-  - "printf 'packages: \"selective-*/*.cabal\"\\n' >> cabal.project"
-  - "printf 'write-ghc-environment-files: always\\n' >> cabal.project"
-  - touch cabal.project.local
-  - "for pkg in $($HCPKG list --simple-output); do echo $pkg | sed 's/-[^-]*$//' | grep -vE -- '^(selective)$' | sed 's/^/constraints: /' | sed 's/$/ installed/' >> cabal.project.local; done"
+  - |
+    echo 'packages: "selective-*/*.cabal"' >> cabal.project
+  - |
+    echo "write-ghc-environment-files: always" >> cabal.project
+  - "for pkg in $($HCPKG list --simple-output); do echo $pkg | sed 's/-[^-]*$//' | (grep -vE -- '^(selective)$' || true) | sed 's/^/constraints: /' | sed 's/$/ installed/' >> cabal.project.local; done"
   - cat cabal.project || true
   - cat cabal.project.local || true
+  # Building...
   # this builds all libraries and executables (without tests/benchmarks)
-  - ${CABAL} new-build -w ${HC} --disable-tests --disable-benchmarks all
-
+  - ${CABAL} v2-build -w ${HC} --disable-tests --disable-benchmarks all | color_cabal_output
+  # Building with tests and benchmarks...
   # 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 selective-* && ${CABAL} check)
-
-  # haddock
-  - ${CABAL} new-haddock -w ${HC} ${TEST} ${BENCH} all
-
-  # Build without installed constraints for packages in global-db
-  - rm -f cabal.project.local; ${CABAL} new-build -w ${HC} --disable-tests --disable-benchmarks all;
+  - ${CABAL} v2-build -w ${HC} ${TEST} ${BENCH} all | color_cabal_output
+  # Testing...
+  - ${CABAL} v2-test -w ${HC} ${TEST} ${BENCH} all | color_cabal_output
+  # cabal check...
+  - (cd selective-* && ${CABAL} -vnormal check)
+  # haddock...
+  - ${CABAL} v2-haddock -w ${HC} ${TEST} ${BENCH} all | color_cabal_output
+  # Building without installed constraints for packages in global-db...
+  - rm -f cabal.project.local
+  - ${CABAL} v2-build -w ${HC} --disable-tests --disable-benchmarks all | color_cabal_output
 
-# REGENDATA ["selective.cabal","--osx=8.6.4","-o",".travis.yml"]
+# REGENDATA ["selective.cabal","--osx=8.6.5","-o",".travis.yml"]
 # EOF
diff --git a/selective.cabal b/selective.cabal
index 6e708c2..d99d6dd 100644
--- a/selective.cabal
+++ b/selective.cabal
@@ -10,10 +10,11 @@ homepage:      https://github.com/snowleopard/selective
 category:      Control
 build-type:    Simple
 cabal-version: 1.18
-tested-with:   GHC==8.0.2,
-               GHC==8.2.2,
-               GHC==8.4.3,
-               GHC==8.6.4
+tested-with:   GHC == 8.0.2,
+               GHC == 8.2.2,
+               GHC == 8.4.3,
+               GHC == 8.6.5,
+               GHC == 8.8.1
 stability:     experimental
 description:   Selective applicative functors: declare your effects statically,
                select which to execute dynamically.
diff --git a/stack.yaml b/stack.yaml
index 44b20d5..019f58c 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,3 +1,3 @@
 packages:
 - '.'
-resolver: lts-13.11
+resolver: lts-13.21