diff --git a/.travis.yml b/.travis.yml
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,146 +1,158 @@
-# This file has been generated -- see https://github.com/hvr/multi-ghc-travis
+# 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:
+      - "\x0313tagged\x03/\x0306%{branch}\x03 \x0314%{commit}\x03 %{build_url} %{message}"
+
 cache:
   directories:
-    - $HOME/.cabsnap
     - $HOME/.cabal/packages
-    - $HOME/.stack
+    - $HOME/.cabal/store
 
 before_cache:
   - rm -fv $HOME/.cabal/packages/hackage.haskell.org/build-reports.log
-  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/00-index.tar
+  # 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:
-    - env: CABALVER=1.16 GHCVER=7.0.4 BUILD=cabal
-      compiler: ": #GHC 7.0.4"
-      addons: {apt: {packages: [cabal-install-1.16,ghc-7.0.4,alex-3.1.4,happy-1.19.5], sources: [hvr-ghc]}}
-
-    - env: CABALVER=1.16 GHCVER=7.2.2 BUILD=cabal
-      compiler: ": #GHC 7.2.2"
-      addons: {apt: {packages: [cabal-install-1.16,ghc-7.2.2,alex-3.1.4,happy-1.19.5], sources: [hvr-ghc]}}
-
-    - env: CABALVER=1.16 GHCVER=7.4.2 BUILD=cabal
-      compiler: ": #GHC 7.4.2"
-      addons: {apt: {packages: [cabal-install-1.16,ghc-7.4.2,alex-3.1.4,happy-1.19.5], sources: [hvr-ghc]}}
-
-    - env: CABALVER=1.16 GHCVER=7.6.3 BUILD=cabal
-      compiler: ": #GHC 7.6.3"
-      addons: {apt: {packages: [cabal-install-1.16,ghc-7.6.3,alex-3.1.4,happy-1.19.5], sources: [hvr-ghc]}}
-
-    - env: CABALVER=1.18 GHCVER=7.8.4 BUILD=cabal
-      compiler: ": #GHC 7.8.4"
-      addons: {apt: {packages: [cabal-install-1.18,ghc-7.8.4,alex-3.1.4,happy-1.19.5], sources: [hvr-ghc]}}
-
-#    - env: BUILD=stack STACK_YAML=stack-7.8.yaml STACK_OPTIONS=--skip-ghc-check
-#      compiler: ": #GHC 7.8.4"
-#      addons: {apt: {packages: [cabal-install-1.18,ghc-7.8.4,alex-3.1.4,happy-1.19.5], sources: [hvr-ghc]}}
-
-#    - env: BUILD=stack STACK_YAML=stack-7.8.yaml
-#      os: osx
-
-    - env: CABALVER=1.22 GHCVER=7.10.1 BUILD=cabal
-      compiler: ": #GHC 7.10.1"
-      addons: {apt: {packages: [cabal-install-1.22,ghc-7.10.1,alex-3.1.4,happy-1.19.5], sources: [hvr-ghc]}}
-
-#    - env: BUILD=stack STACK_OPTIONS=--skip-ghc-check
-#      compiler: ": #GHC 7.10.1"
-#      addons: {apt: {packages: [cabal-install-1.22,ghc-7.10.1,alex-3.1.4,happy-1.19.5], sources: [hvr-ghc]}}
-
-    - env: CABALVER=1.22 GHCVER=7.10.3 BUILD=cabal
-      compiler: ": #GHC 7.10.3"
-      addons: {apt: {packages: [cabal-install-1.22,ghc-7.10.3,alex-3.1.4,happy-1.19.5], sources: [hvr-ghc]}}
-
-    - env: CABALVER=1.24 GHCVER=8.0.1 BUILD=cabal
-      compiler: ": #GHC 8.0.1"
-      addons: {apt: {packages: [cabal-install-1.24,ghc-8.0.1,alex-3.1.4,happy-1.19.5], sources: [hvr-ghc]}}
-
-    - env: CABALVER=head GHCVER=head BUILD=cabal
-      compiler: ": #GHC head"
-      addons: {apt: {packages: [cabal-install-head,ghc-head,alex-3.1.4,happy-1.19.5], sources: [hvr-ghc]}}
-
-#    - env: BUILD=stack
-#      os: osx
+    - 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: TEST=--disable-tests BENCH=--disable-benchmarks
+      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:
-    - env: CABALVER=1.16 GHCVER=7.0.4 BUILD=cabal
-    - env: CABALVER=1.16 GHCVER=7.2.2 BUILD=cabal
-    - env: CABALVER=head GHCVER=head BUILD=cabal
+    - compiler: "ghc-head"
+    - compiler: "ghc-7.0.4"
+    - compiler: "ghc-7.2.2"
+    - compiler: "ghc-8.6.1"
 
 before_install:
- - unset CC
- - case "$BUILD" in
-     stack)
-       export STACK_VERSION=0.1.3.0;
-       mkdir -p ~/bin;
-       travis_retry curl -L https://github.com/commercialhaskell/stack/releases/download/v$STACK_VERSION/stack-$STACK_VERSION-x86_64-$TRAVIS_OS_NAME.gz | gunzip > ~/bin/stack;
-       chmod a+x ~/bin/stack;
-       scripts/travis_long stack --no-terminal setup;
-       export PATH=~/bin:$PATH;;
-     cabal)
-       export HAPPYVER=1.19.5
-       export ALEXVER=3.1.4
-       export PATH=~/.cabal/bin:/opt/ghc/$GHCVER/bin:/opt/cabal/$CABALVER/bin:/opt/happy/$HAPPYVER/bin:/opt/alex/$ALEXVER/bin:$PATH;;
-   esac
+  - 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 $HCNUMVER
+
 install:
- - case "$BUILD" in
-     stack)
-       scripts/travis_long stack --no-terminal $STACK_OPTIONS build --only-snapshot -j2;;
-     cabal)
-       echo "$(ghc --version) [$(ghc --print-project-git-commit-id 2> /dev/null || echo '?')]"
-       cabal --version;
-       if [ -f $HOME/.cabal/packages/hackage.haskell.org/00-index.tar.gz ];
-       then
-         zcat $HOME/.cabal/packages/hackage.haskell.org/00-index.tar.gz >
-              $HOME/.cabal/packages/hackage.haskell.org/00-index.tar;
-       fi;
-       travis_retry cabal update;
-       cabal install --only-dependencies --enable-tests --enable-benchmarks --dry -v > installplan.txt;
-       sed -i -e '1,/^Resolving /d' installplan.txt; cat installplan.txt;
-       if diff -u installplan.txt $HOME/.cabsnap/installplan.txt; then
-         echo "cabal build-cache HIT";
-         rm -rfv .ghc;
-         cp -a $HOME/.cabsnap/ghc $HOME/.ghc;
-         cp -a $HOME/.cabsnap/lib $HOME/.cabsnap/share $HOME/.cabsnap/bin $HOME/.cabal/;
-       else
-         echo "cabal build-cache MISS";
-         rm -rf $HOME/.cabsnap;
-         mkdir -p $HOME/.ghc $HOME/.cabal/lib $HOME/.cabal/share $HOME/.cabal/bin;
-         cabal install --only-dependencies --enable-tests --enable-benchmarks;
-         if [ "$GHCVER" = "7.10.1" ]; then cabal install Cabal-1.22.4.0; fi;
-       fi;
-       if [ ! -d $HOME/.cabsnap ]; then
-         echo "snapshotting package-db to build-cache";
-         mkdir $HOME/.cabsnap;
-         cp -a $HOME/.ghc $HOME/.cabsnap/ghc;
-         cp -a $HOME/.cabal/lib $HOME/.cabal/share $HOME/.cabal/bin installplan.txt $HOME/.cabsnap/;
-       fi;;
-   esac
+  - cabal --version
+  - echo "$(${HC} --version) [$(${HC} --print-project-git-commit-id 2> /dev/null || echo '?')]"
+  - BENCH=${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
 
-# snapshot package-db on cache miss
+      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: \".\"\\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
+  - rm -f cabal.project.freeze
+  - cabal new-build -w ${HC} ${TEST} ${BENCH} --project-file="cabal.project" --dep -j2 all
+  - rm -rf .ghc.environment.* "."/dist
+  - DISTDIR=$(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.
 script:
- - case "$BUILD" in
-     stack)
-       scripts/travis_long stack --no-terminal $STACK_OPTIONS build -j2;;
-     cabal)
-       cabal configure --enable-tests -v2;
-       cabal build;
-       cabal test;
-       cabal bench || true;
-       cabal sdist || true;
-       SRC_TGZ=$(cabal info . | awk '{print $2;exit}').tar.gz && (cd dist && cabal install --force-reinstalls "$SRC_TGZ");;
-   esac
+  # test that source-distributions can be generated
+  - (cd "." && cabal sdist)
+  - mv "."/dist/tagged-*.tar.gz ${DISTDIR}/
+  - cd ${DISTDIR} || false
+  - find . -maxdepth 1 -name '*.tar.gz' -exec tar -xvf '{}' \;
+  - "printf 'packages: tagged-*/*.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
 
-notifications:
-  irc:
-    channels:
-      - "irc.freenode.org#haskell-lens"
-    skip_join: true
-    template:
-      - "\x0313tagged\x0f/\x0306%{branch}\x0f \x0314%{commit}\x0f %{message} \x0302\x1f%{build_url}\x0f"
+  # build & run tests, build benchmarks
+  - cabal new-build -w ${HC} ${TEST} ${BENCH} all
+
+  # cabal check
+  - (cd tagged-* && 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 +1,12 @@
+0.8.6 [2018.07.02]
+------------------
+* Make the `Read(1)` instances for `Proxy` ignore the precedence argument,
+  mirroring similar changes to `base`
+  [here](http://git.haskell.org/ghc.git/commitdiff/8fd959998e900dffdb7f752fcd42df7aaedeae6e).
+* Fix a bug in the `Floating` instance for `Tagged` in which `logBase` was
+  defined in terms of `(**)`.
+* Avoid incurring some dependencies when using recent GHCs.
+
 0.8.5
 -----
 * Support `Data.Bifoldable`/`Data.Bitraversable` in `base` for GHC 8.1+.
diff --git a/old/Data/Proxy.hs b/old/Data/Proxy.hs
--- a/old/Data/Proxy.hs
+++ b/old/Data/Proxy.hs
@@ -98,7 +98,7 @@
   showsPrec _ _ = showString "Proxy"
 
 instance Read (Proxy s) where
-  readsPrec d = readParen (d > 10) (\r -> [(Proxy, s) | ("Proxy",s) <- lex r ])
+  readsPrec _ = readParen False (\r -> [(Proxy, s) | ("Proxy",s) <- lex r ])
 
 #ifdef __GLASGOW_HASKELL__
 #if __GLASGOW_HASKELL__ < 707
@@ -186,8 +186,8 @@
   liftShowsPrec _ _ _ _ = showString "Proxy"
 
 instance Read1 Proxy where
-  liftReadsPrec _ _ d =
-    readParen (d > 10) (\r -> [(Proxy, s) | ("Proxy",s) <- lex r ])
+  liftReadsPrec _ _ _ =
+    readParen False (\r -> [(Proxy, s) | ("Proxy",s) <- lex r ])
 # endif
 #endif
 
diff --git a/src/Data/Tagged.hs b/src/Data/Tagged.hs
--- a/src/Data/Tagged.hs
+++ b/src/Data/Tagged.hs
@@ -43,7 +43,7 @@
     , reproxy
     ) where
 
-#if __GLASGOW_HASKELL__ >= 710
+#if MIN_VERSION_base(4,8,0)
 import Control.Applicative (liftA2)
 #else
 import Control.Applicative ((<$>), liftA2, Applicative(..))
@@ -63,10 +63,10 @@
                             )
 #endif
 import Control.Monad (liftM)
-#if __GLASGOW_HASKELL__ >= 709
+#if MIN_VERSION_base(4,8,0)
 import Data.Bifunctor
 #endif
-#if __GLASGOW_HASKELL__ >= 801
+#if MIN_VERSION_base(4,10,0)
 import Data.Bifoldable (Bifoldable(..))
 import Data.Bitraversable (Bitraversable(..))
 #endif
@@ -77,7 +77,7 @@
 #if __GLASGOW_HASKELL__ < 707
 import Data.Proxy
 #endif
-#if __GLASGOW_HASKELL__ >= 800
+#if MIN_VERSION_base(4,9,0)
 import Data.Semigroup (Semigroup(..))
 #endif
 import Data.String (IsString(..))
@@ -157,7 +157,7 @@
     readsPrec d = readParen (d > 10) $ \r ->
         [(Tagged a, t) | ("Tagged", s) <- lex r, (a, t) <- readsPrec 11 s]
 
-#if __GLASGOW_HASKELL__ >= 800
+#if MIN_VERSION_base(4,9,0)
 instance Semigroup a => Semigroup (Tagged s a) where
     Tagged a <> Tagged b = Tagged (a <> b)
     stimes n (Tagged a)  = Tagged (stimes n a)
@@ -175,14 +175,14 @@
     fmap f (Tagged x) = Tagged (f x)
     {-# INLINE fmap #-}
 
-#if __GLASGOW_HASKELL__ >= 709
+#if MIN_VERSION_base(4,8,0)
 -- this instance is provided by the bifunctors package for GHC<7.9
 instance Bifunctor Tagged where
     bimap _ g (Tagged b) = Tagged (g b)
     {-# INLINE bimap #-}
 #endif
 
-#if __GLASGOW_HASKELL__ >= 801
+#if MIN_VERSION_base(4,10,0)
 -- these instances are provided by the bifunctors package for GHC<8.1
 instance Bifoldable Tagged where
     bifoldMap _ g (Tagged b) = g b
@@ -341,7 +341,7 @@
     acosh = fmap acosh
     atanh = fmap atanh
     (**) = liftA2 (**)
-    logBase = liftA2 (**)
+    logBase = liftA2 logBase
 
 instance RealFrac a => RealFrac (Tagged s a) where
     properFraction (Tagged x) = (a, Tagged b) where
@@ -385,20 +385,20 @@
     testBit (Tagged a) i = testBit a i
     isSigned (Tagged a) = isSigned a
     bitSize (Tagged a) = bitSize a -- deprecated, but still required :(
-#if __GLASGOW_HASKELL__ >= 704
+#if MIN_VERSION_base(4,5,0)
     unsafeShiftL (Tagged a) i = Tagged (unsafeShiftL a i)
     unsafeShiftR (Tagged a) i = Tagged (unsafeShiftR a i)
     popCount (Tagged a) = popCount a
 #endif
-#if __GLASGOW_HASKELL__ >= 708
+#if MIN_VERSION_base(4,7,0)
     bitSizeMaybe (Tagged a) = bitSizeMaybe a
     zeroBits = Tagged zeroBits
 #endif
 
-#if __GLASGOW_HASKELL__ >= 708
+#if MIN_VERSION_base(4,7,0)
 instance FiniteBits a => FiniteBits (Tagged s a) where
     finiteBitSize (Tagged a) = finiteBitSize a
-# if __GLASGOW_HASKELL__ >= 710
+# if MIN_VERSION_base(4,8,0)
     countLeadingZeros (Tagged a) = countLeadingZeros a
     countTrailingZeros (Tagged a) = countTrailingZeros a
 # endif
diff --git a/tagged.cabal b/tagged.cabal
--- a/tagged.cabal
+++ b/tagged.cabal
@@ -1,5 +1,5 @@
 name:           tagged
-version:        0.8.5
+version:        0.8.6
 license:        BSD3
 license-file:   LICENSE
 author:         Edward A. Kmett
@@ -10,10 +10,20 @@
 homepage:       http://github.com/ekmett/tagged
 bug-reports:    http://github.com/ekmett/tagged/issues
 copyright:      2009-2015 Edward A. Kmett
-description:    Haskell 98 phantom types to avoid unsafely passing dummy arguments
+description:    Haskell 98 phantom types to avoid unsafely passing dummy arguments.
 build-type:     Simple
 cabal-version:  >= 1.10
 extra-source-files: .travis.yml CHANGELOG.markdown README.markdown HLint.hs
+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
 
 source-repository head
   type: git
@@ -57,11 +67,16 @@
 
   if impl(ghc>=7.6)
     exposed-modules: Data.Proxy.TH
-    build-depends: template-haskell >= 2.8 && < 2.12
+    build-depends: template-haskell >= 2.8 && < 2.15
 
   if flag(deepseq)
     build-depends: deepseq >= 1.1 && < 1.5
 
   if flag(transformers)
-    build-depends: transformers        >= 0.2 && < 0.6,
-                   transformers-compat >= 0.5 && < 1
+    build-depends: transformers        >= 0.2 && < 0.6
+
+    -- Ensure Data.Functor.Classes is always available
+    if impl(ghc >= 7.10) || impl(ghcjs)
+      build-depends: transformers >= 0.4.2.0
+    else
+      build-depends: transformers-compat >= 0.5 && < 1
