diff --git a/.travis.yml b/.travis.yml
index 67153ec..706d2fb 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,6 @@
 # This Travis job script has been generated by a script via
 #
-#   make_travis_yml_2.hs '--branch' 'master' '-o' '.travis.yml' 'servant-quickcheck.cabal'
+#   runghc make_travis_yml_2.hs '--branch' 'master' '-o' '.travis.yml' 'servant-quickcheck.cabal'
 #
 # For more information, see https://github.com/hvr/multi-ghc-travis
 #
@@ -28,6 +28,8 @@ before_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-7.10.3"
@@ -36,15 +38,19 @@ matrix:
     - compiler: "ghc-8.0.2"
     # env: TEST=--disable-tests BENCH=--disable-benchmarks
       addons: {apt: {packages: [ghc-ppa-tools,cabal-install-head,ghc-8.0.2], sources: [hvr-ghc]}}
-    - compiler: "ghc-8.2.1"
+    - compiler: "ghc-8.2.2"
     # env: TEST=--disable-tests BENCH=--disable-benchmarks
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-head,ghc-8.2.1], sources: [hvr-ghc]}}
+      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-head,ghc-8.2.2], sources: [hvr-ghc]}}
 
 before_install:
   - HC=${CC}
   - HCPKG=${HC/ghc/ghc-pkg}
   - unset CC
-  - PATH=/opt/ghc/bin:/opt/ghc-ppa-tools/bin:$PATH
+  - ROOTDIR=$(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
@@ -53,12 +59,15 @@ install:
   - TEST=${TEST---enable-tests}
   - HADDOCK=${HADDOCK-true}
   - INSTALLED=${INSTALLED-true}
+  - GHCHEAD=${GHCHEAD-false}
   - travis_retry cabal update -v
-  - sed -i.bak 's/^jobs:/-- jobs:/' ${HOME}/.cabal/config
-  - rm -fv cabal.project.local
-  - "echo 'packages: .' > cabal.project"
+  - "sed -i.bak 's/^jobs:/-- jobs:/' ${HOME}/.cabal/config"
+  - rm -fv cabal.project cabal.project.local
+  - grep -Ev -- '^\s*--' ${HOME}/.cabal/config | grep -Ev '^\s*$'
+  - "printf 'packages: \".\"\\n' > cabal.project"
+  - cat cabal.project
   - if [ -f "./configure.ac" ]; then
-      (cd "."; autoreconf -i);
+      (cd "." && autoreconf -i);
     fi
   - rm -f cabal.project.freeze
   - cabal new-build -w ${HC} ${TEST} ${BENCH} --project-file="cabal.project" --dep -j2 all
@@ -70,26 +79,28 @@ install:
 # 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 "." && cabal sdist)
   - mv "."/dist/servant-quickcheck-*.tar.gz ${DISTDIR}/
-  - cd ${DISTDIR}
+  - cd ${DISTDIR} || false
   - find . -maxdepth 1 -name '*.tar.gz' -exec tar -xvf '{}' \;
-  - "printf 'packages: servant-quickcheck-*/*.cabal\n' > cabal.project"
+  - "printf 'packages: servant-quickcheck-*/*.cabal\\n' > cabal.project"
+  - cat cabal.project
   # this builds all libraries and executables (without tests/benchmarks)
   - cabal new-build -w ${HC} --disable-tests --disable-benchmarks all
 
   # Build with installed constraints for packages in global-db
-  - if $INSTALLED; then
-      echo cabal new-build -w ${HC} --disable-tests --disable-benchmarks $(${HCPKG} list --global --simple-output --names-only | sed 's/\([a-zA-Z0-9-]\{1,\}\) */--constraint="\1 installed" /g') all | sh;
-    else echo "Not building with installed constraints"; fi
+  - if $INSTALLED; then echo cabal new-build -w ${HC} --disable-tests --disable-benchmarks $(${HCPKG} list --global --simple-output --names-only | sed 's/\([a-zA-Z0-9-]\{1,\}\) */--constraint="\1 installed" /g') all | sh; else echo "Not building with installed constraints"; fi
 
   # 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} ${TEST} all; fi
+  - if [ "x$TEST" = "x--enable-tests" ]; then cabal new-test -w ${HC} ${TEST} ${BENCH} all; fi
+
+  # cabal check
+  - (cd servant-quickcheck-* && cabal check)
 
   # haddock
   - rm -rf ./dist-newstyle
-  - if $HADDOCK; then cabal new-haddock -w ${HC} --disable-tests --disable-benchmarks all; else echo "Skipping haddock generation";fi
+  - if $HADDOCK; then cabal new-haddock -w ${HC} ${TEST} ${BENCH} all; else echo "Skipping haddock generation";fi
 
 # REGENDATA ["--branch","master","-o",".travis.yml","servant-quickcheck.cabal"]
 # EOF
diff --git a/CHANGELOG.yaml b/CHANGELOG.yaml
index 435c0e5..f801cdc 100644
--- a/CHANGELOG.yaml
+++ b/CHANGELOG.yaml
@@ -2,6 +2,14 @@ upcoming:
 
 releases:
 
+  - version: "0.0.6.0"
+    changes:
+
+      - description: Support for servant-0.12
+        issue: none
+        authors: phadej
+        date: 2018-02-09
+
   - version: "0.0.5.0"
     changes:
 
diff --git a/example/Main.hs b/example/Main.hs
new file mode 100644
index 0000000..1a80724
--- /dev/null
+++ b/example/Main.hs
@@ -0,0 +1,31 @@
+{-# LANGUAGE OverloadedStrings, DataKinds #-}
+module Main (main) where
+
+import Servant
+import Servant.QuickCheck
+import Test.Hspec
+import Data.Text (Text)
+import System.Environment (getArgs)
+
+main :: IO ()
+main = do
+    args <- getArgs
+    case args of
+        [] -> putStrLn "Not running without arguments. Try --help or --fail-fast."
+        _  -> hspec spec
+
+-- Change to String to reproduce
+-- https://github.com/haskell-servant/servant-quickcheck/issues/41
+type API = Get '[PlainText] Text
+
+api :: Proxy API
+api = Proxy
+
+server :: Server API
+server = return "Sigurð Fáfnirslayer"
+
+spec :: Spec
+spec = describe "example server" $
+    it "mangles UTF-8 in error messages" $
+        withServantServer api (return server) $ \burl ->
+            serverSatisfies api burl defaultArgs (getsHaveCacheControlHeader <%> mempty)
diff --git a/servant-quickcheck.cabal b/servant-quickcheck.cabal
index 32a0f48..bcc0b5e 100644
--- a/servant-quickcheck.cabal
+++ b/servant-quickcheck.cabal
@@ -1,5 +1,5 @@
 name:                servant-quickcheck
-version:             0.0.5.0
+version:             0.0.6.0
 synopsis:            QuickCheck entire APIs
 description:
  This packages provides QuickCheck properties that are tested across an entire
@@ -17,7 +17,7 @@ extra-source-files:
 tested-with:
   GHC==7.10.3,
   GHC==8.0.2,
-  GHC==8.2.1
+  GHC==8.2.2
 
 source-repository head
   type: git
@@ -45,14 +45,14 @@ library
                      , hspec >= 2.2 && < 2.5
                      , http-client >= 0.4.30 && < 0.6
                      , http-media >= 0.6 && <0.8
-                     , http-types > 0.8 && < 0.11
+                     , http-types > 0.8 && < 0.13
                      , mtl > 2.1 && < 2.3
                      , pretty == 1.1.*
                      , process >= 1.2 && < 1.7
-                     , QuickCheck > 2.7 && < 2.11
-                     , servant > 0.6 && < 0.13
-                     , servant-client > 0.6 && < 0.13
-                     , servant-server > 0.6 && < 0.13
+                     , QuickCheck > 2.7 && < 2.12
+                     , servant >= 0.13 && < 0.14
+                     , servant-client >= 0.13 && < 0.14
+                     , servant-server >= 0.13 && < 0.14
                      , split == 0.2.*
                      , string-conversions > 0.3 && < 0.5
                      , temporary == 1.2.*
@@ -114,3 +114,17 @@ test-suite spec
                      , ScopedTypeVariables
   if flag(long-tests)
       cpp-options: -DLONG_TESTS
+
+test-suite example
+  type: exitcode-stdio-1.0
+  main-is: Main.hs
+  hs-source-dirs:
+    example
+  ghc-options: -Wall
+  build-depends:
+      base
+    , hspec
+    , servant-server
+    , servant-quickcheck
+    , text
+  default-language: Haskell2010
diff --git a/src/Servant/QuickCheck/Internal/HasGenRequest.hs b/src/Servant/QuickCheck/Internal/HasGenRequest.hs
index bc6fbd9..5f945ee 100644
--- a/src/Servant/QuickCheck/Internal/HasGenRequest.hs
+++ b/src/Servant/QuickCheck/Internal/HasGenRequest.hs
@@ -78,7 +78,7 @@ instance HasGenRequest api => HasGenRequest (Description d :> api) where
 #endif
 
 instance (Arbitrary c, HasGenRequest b, ToHttpApiData c )
-    => HasGenRequest (Capture x c :> b) where
+    => HasGenRequest (Capture' mods x c :> b) where
     genRequest _ = (oldf, do
       old' <- old
       new' <- toUrlPiece <$> new
@@ -101,10 +101,10 @@ instance (Arbitrary c, HasGenRequest b, ToHttpApiData c )
 #endif
 
 instance (Arbitrary c, KnownSymbol h, HasGenRequest b, ToHttpApiData c)
-    => HasGenRequest (Header h c :> b) where
+    => HasGenRequest (Header' mods h c :> b) where
     genRequest _ = (oldf, do
       old' <- old
-      new' <- toUrlPiece <$> new
+      new' <- toUrlPiece <$> new  -- TODO: generate lenient or/and optional
       return $ \burl -> let r = old' burl in r {
           requestHeaders = (hdr, cs new') : requestHeaders r })
       where
@@ -113,9 +113,9 @@ instance (Arbitrary c, KnownSymbol h, HasGenRequest b, ToHttpApiData c)
         new = arbitrary :: Gen c
 
 instance (AllMimeRender x c, Arbitrary c, HasGenRequest b)
-    => HasGenRequest (ReqBody x c :> b) where
+    => HasGenRequest (ReqBody' mods x c :> b) where
     genRequest _ = (oldf, do
-      old' <- old
+      old' <- old  -- TODO: generate lenient
       new' <- new
       (ct, bd) <- elements $ allMimeRender (Proxy :: Proxy x) new'
       return $ \burl -> let r = old' burl in r {
@@ -127,9 +127,9 @@ instance (AllMimeRender x c, Arbitrary c, HasGenRequest b)
         new = arbitrary :: Gen c
 
 instance (KnownSymbol x, Arbitrary c, ToHttpApiData c, HasGenRequest b)
-    => HasGenRequest (QueryParam x c :> b) where
+    => HasGenRequest (QueryParam' mods x c :> b) where
     genRequest _ = (oldf, do
-      new' <- new
+      new' <- new  -- TODO: generate lenient or/and optional
       old' <- old
       return $ \burl -> let r = old' burl
                             newExpr = param <> "=" <> cs (toQueryParam new')