diff --git a/CHANGES.markdown b/CHANGES.markdown
--- a/CHANGES.markdown
+++ b/CHANGES.markdown
@@ -1,8 +1,15 @@
+# 0.2.1
+  * C include directories (Cabal field: `include-dirs`) are now passed to GHC when parsing source files ([#7](https://github.com/martijnbastiaan/doctest-parallel/issues/7))
+  * A migration guide has been added ([#11](https://github.com/martijnbastiaan/doctest-parallel/issues/11))
+  * Test order can be randomized using `--randomize-order`. Test order can be made deterministic by adding an optional `--seed=N` argument ([#12](https://github.com/martijnbastiaan/doctest-parallel/pull/12))
+  * Any non-error output can now be surpressed by `--quiet` ([#20](https://github.com/martijnbastiaan/doctest-parallel/pull/20))
+  * Doctest can now be called using a record for option passing in addition to command line arguments. See `mainFromCabalWithConfig` and `mainFromLibraryWithConfig`.
+
 # 0.2
 Changes:
   * Support for GHC 9.2 has been added ([#4](https://github.com/martijnbastiaan/doctest-parallel/pull/4))
   * Support for GHC 8.2 has been dropped ([#3](https://github.com/martijnbastiaan/doctest-parallel/pull/3))
-  * The dependency `cabal-install-parsers` has been dropped. This trims the dependency tree quite a bit [#3](https://github.com/martijnbastiaan/doctest-parallel/pull/3)
+  * The dependency `cabal-install-parsers` has been dropped. This trims the dependency tree quite a bit ([#3](https://github.com/martijnbastiaan/doctest-parallel/pull/3))
   * The Hackage distribution now ships all files necessary to run `doctest-parallel`'s tests (Fixes [#1](https://github.com/martijnbastiaan/doctest-parallel/issues/1), PR [#2](https://github.com/martijnbastiaan/doctest-parallel/pull/2))
 
 # 0.1
diff --git a/README.markdown b/README.markdown
--- a/README.markdown
+++ b/README.markdown
@@ -6,6 +6,9 @@
 # Installation
 `doctest-parallel` is available from [Hackage](https://hackage.haskell.org/package/doctest-parallel). It cannot be used as a standalone binary, rather, it expects to be integrated in a Cabal/Stack project. See [examples/](example/README.md) for more information on how to integrate `doctest-parallel` into your project.
 
+# Migrating from `doctest`
+See [issue #11](https://github.com/martijnbastiaan/doctest-parallel/issues/11) for more information.
+
 # Usage
 Below is a small Haskell module. The module contains a Haddock comment with some examples of interaction. The examples demonstrate how the module is supposed to be used.
 
@@ -329,7 +332,8 @@
  * It would be lovely if we could get rid of the needs for `write-ghc-environment-files: always` option for Cabal. To properly do this, I think Cabal should do two things:
     1. Deprecate GHC environment files as a way to _implicitly_ setup environments. Instead, environment files should be written to the `dist-newstyle` directory and activated using some subcommand, e.g. `cabal shell`. This avoids the many problems GHC environment files have, while retaining their functionality for people who like them.
     2. Any subcommands should be run with `GHC_ENVIRONMENT` set - pointing to the GHC environment file. Like Stack, this would create a hassle free way of using Cabal in combination with projects/executables that use the GHC API (e.g., `clash-ghc`, `doctest-parallel`).
- * Cabal needs to expose more information _by default_ in order for `doctest-parallel` to properly work. Specifically, it needs to know the exact `default-extensions`, `ghc-options`, and `CPP` flags the project is compiled with. These options are obtainable by using a custom `Setup.hs`, but this has its own list of problems.
+ * It would be nice if Cabal would expose more information _by default_ (probably through auto-generated modules) in order for `doctest-parallel` to properly work. Specifically, it needs to know the exact `default-extensions`, `ghc-options`, and `CPP` flags the project is compiled with. These options are obtainable by using a custom `Setup.hs`, but this has its own list of problems.
+   * Alternatively, if comments could be included in and loaded from `.hi` files that'd solve all issues too.
  * Hopefully many of the improvements made here can make their way back into `sol/doctest`.
 
  Of course, if you wish to add a feature that's not in this list, please feel free top open a pull request!
diff --git a/doctest-parallel.cabal b/doctest-parallel.cabal
--- a/doctest-parallel.cabal
+++ b/doctest-parallel.cabal
@@ -1,7 +1,7 @@
 cabal-version: 2.0
 
 name:           doctest-parallel
-version:        0.2
+version:        0.2.1
 synopsis:       Test interactive Haskell examples
 description:    The doctest program checks examples in source code comments.  It is modeled
                 after doctest for Python (<https://docs.python.org/3/library/doctest.html>).
@@ -54,6 +54,7 @@
     test/parse/setup-empty/*.hs
     test/parse/setup-only/*.hs
     test/parse/simple/*.hs
+    test/integration/WithCInclude/include/WithCInclude.h
 
 source-repository head
   type: git
@@ -97,6 +98,7 @@
     , ghc-paths >=0.1.0.9
     , pretty
     , process
+    , random >= 1.2
     , syb >=0.3
     , transformers
     , unordered-containers
@@ -118,6 +120,8 @@
   -- ghc-options: -Wall
   hs-source-dirs:
       test/integration
+  include-dirs:
+      test/integration/WithCInclude/include
   c-sources:
       test/integration/WithCbits/foo.c
   exposed-modules:
@@ -157,6 +161,7 @@
     TestSimple.Fib
     TrailingWhitespace.Foo
     WithCbits.Bar
+    WithCInclude.Bar
 
 test-suite spectests
   main-is: Spec.hs
@@ -185,6 +190,7 @@
     , base >=4.5 && <5
     , base-compat >=0.7.0
     , code-page >=0.1
+    , containers
     , doctest-parallel
     , deepseq
     , directory
diff --git a/src/Test/DocTest.hs b/src/Test/DocTest.hs
--- a/src/Test/DocTest.hs
+++ b/src/Test/DocTest.hs
@@ -1,11 +1,21 @@
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE ViewPatterns #-}
 
-module Test.DocTest where
+module Test.DocTest
+  ( mainFromCabal
+  , mainFromLibrary
+  , mainFromCabalWithConfig
+  , mainFromLibraryWithConfig
 
+  -- * Internal
+  , filterModules
+  , isSuccess
+  , getSeed
+  , run
+  ) where
+
 import           Prelude ()
 import           Prelude.Compat
 
@@ -14,6 +24,7 @@
 import           Control.Monad (unless)
 import           System.Exit (exitFailure)
 import           System.IO
+import           System.Random (randomIO)
 
 import qualified Control.Exception as E
 
@@ -40,13 +51,29 @@
 --
 -- Example:
 --
+-- @
 -- mainFromCabal "my-project" =<< getArgs
+-- @
 --
 mainFromCabal :: String -> [String] -> IO ()
 mainFromCabal libName cmdArgs = do
   lib <- extractCabalLibrary =<< findCabalPackage libName
   mainFromLibrary lib cmdArgs
 
+-- | Run doctest given config.
+--
+-- Example:
+--
+-- @
+-- mainFromCabal "my-project" defaultConfig
+-- @
+--
+mainFromCabalWithConfig :: String -> Config -> IO ()
+mainFromCabalWithConfig libName config = do
+  lib <- extractCabalLibrary =<< findCabalPackage libName
+  mainFromLibraryWithConfig lib config
+
+-- | Like 'mainFromCabal', but with a given library.
 mainFromLibrary :: Library -> [String] -> IO ()
 mainFromLibrary lib (parseOptions -> opts) =
   case opts of
@@ -56,15 +83,20 @@
        hPutStrLn stderr "Try `doctest --help' for more information."
        exitFailure
     Result config -> do
-      r <- main lib config `E.catch` \e -> do
-        case fromException e of
-          Just (UsageError err) -> do
-            hPutStrLn stderr ("doctest: " ++ err)
-            hPutStrLn stderr "Try `doctest --help' for more information."
-            exitFailure
-          _ -> E.throwIO e
-      unless (isSuccess r) exitFailure
+      mainFromLibraryWithConfig lib config
 
+-- | Run doctests with given library and config.
+mainFromLibraryWithConfig :: Library -> Config -> IO ()
+mainFromLibraryWithConfig lib config = do
+  r <- run lib config `E.catch` \e -> do
+    case fromException e of
+      Just (UsageError err) -> do
+        hPutStrLn stderr ("doctest: " ++ err)
+        hPutStrLn stderr "Try `doctest --help' for more information."
+        exitFailure
+      _ -> E.throwIO e
+  unless (isSuccess r) exitFailure
+
 isSuccess :: Summary -> Bool
 isSuccess s = sErrors s == 0 && sFailures s == 0
 
@@ -83,15 +115,36 @@
   nonExistingMods = Set.toList (wantedMods1 `Set.difference` allMods1)
   isSpecifiedMod Module{moduleName} = moduleName `Set.member` wantedMods1
 
+getSeed
+  :: Bool
+  -- ^ Whether quiet mode is enabled
+  -> Bool
+  -- ^ Enable order randomization. If 'False', this function always returns 'Nothing'
+  -> Maybe Int
+  -- ^ User supplied seed. If 'Nothing', a fresh seed will be generated.
+  -> IO (Maybe Int)
+  -- ^ Maybe seed to use for order randomization.
+getSeed _quiet False _ = pure Nothing
+getSeed _quiet True (Just seed) = pure (Just seed)
+getSeed quiet True Nothing = do
+  -- Using an abslute number to prevent copy+paste errors
+  seed <- abs <$> randomIO
+  unless quiet $
+    putStrLn ("Using freshly generated seed to randomize test order: " <> show seed)
+  pure (Just seed)
 
-main :: Library -> Config -> IO Summary
-main lib Config{..} = do
+-- | Run doctest for given library and config. Produce a summary of all tests.
+run :: Library -> Config -> IO Summary
+run lib Config{..} = do
   let
     implicitPrelude = DisableExtension ImplicitPrelude `notElem` libDefaultExtensions lib
     (includeArgs, moduleArgs, otherGhciArgs) = libraryToGhciArgs lib
     evalGhciArgs = otherGhciArgs ++ ["-XNoImplicitPrelude"]
 
+  seed <- getSeed cfgQuiet cfgRandomizeOrder cfgSeed
+
   -- get examples from Haddock comments
   allModules <- getDocTests (includeArgs ++ moduleArgs ++ otherGhciArgs)
-  let modules = filterModules cfgModules allModules
-  runModules cfgThreads cfgPreserveIt cfgVerbose implicitPrelude evalGhciArgs modules
+  runModules
+    cfgThreads cfgPreserveIt cfgVerbose seed implicitPrelude evalGhciArgs
+    cfgQuiet (filterModules cfgModules allModules)
diff --git a/src/Test/DocTest/Helpers.hs b/src/Test/DocTest/Helpers.hs
--- a/src/Test/DocTest/Helpers.hs
+++ b/src/Test/DocTest/Helpers.hs
@@ -1,6 +1,5 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE MultiWayIf #-}
-{-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE LambdaCase #-}
 
@@ -25,7 +24,7 @@
 import Distribution.PackageDescription
   ( CondTree(CondNode, condTreeData), GenericPackageDescription (condLibrary)
   , exposedModules, libBuildInfo, hsSourceDirs, defaultExtensions, package
-  , packageDescription, condSubLibraries )
+  , packageDescription, condSubLibraries, includeDirs )
 import Distribution.Pretty (prettyShow)
 import Distribution.Verbosity (silent)
 
@@ -38,16 +37,22 @@
 
 data Library = Library
   { libSourceDirectories :: [FilePath]
+    -- ^ Haskell source directories
+  , libCSourceDirectories :: [FilePath]
+    -- ^ C source directories
   , libModules :: [ModuleName]
+    -- ^ Exposed modules
   , libDefaultExtensions :: [Extension]
+    -- ^ Extensions enabled by default
   }
   deriving (Show)
 
 -- | Convert a "Library" to arguments suitable to be passed to GHCi.
 libraryToGhciArgs :: Library -> ([String], [String], [String])
-libraryToGhciArgs Library{..} = (srcArgs, modArgs, extArgs)
+libraryToGhciArgs Library{..} = (hsSrcArgs <> cSrcArgs, modArgs, extArgs)
  where
-  srcArgs = map ("-i" <>) libSourceDirectories
+  hsSrcArgs = map ("-i" <>) libSourceDirectories
+  cSrcArgs = map ("-I" <>) libCSourceDirectories
   modArgs = map prettyShow libModules
   extArgs = map showExt libDefaultExtensions
 
@@ -144,10 +149,12 @@
     let
       buildInfo = libBuildInfo lib
       sourceDirs = hsSourceDirs buildInfo
+      cSourceDirs = includeDirs buildInfo
       root = takeDirectory pkgPath
     in
       pure Library
         { libSourceDirectories = map ((root </>) . compatPrettyShow) sourceDirs
+        , libCSourceDirectories = map (root </>) cSourceDirs
         , libModules = exposedModules lib
         , libDefaultExtensions = defaultExtensions buildInfo
         }
diff --git a/src/Test/DocTest/Internal/Options.hs b/src/Test/DocTest/Internal/Options.hs
--- a/src/Test/DocTest/Internal/Options.hs
+++ b/src/Test/DocTest/Internal/Options.hs
@@ -24,15 +24,18 @@
 usage :: String
 usage = unlines [
     "Usage:"
-  , "  doctest [ --fast | --preserve-it | --verbose | -jN ]..."
+  , "  doctest [ options ]... [<module>]..."
   , "  doctest --help"
   , "  doctest --version"
   , "  doctest --info"
   , ""
   , "Options:"
   , "  -jN                      number of threads to use"
+  , "  --randomize-order        randomize order in which tests are run"
+  , "  --seed                   use a specific seed to randomize test order"
   , "  --preserve-it            preserve the `it` variable between examples"
   , "  --verbose                print each test as it is run"
+  , "  --quiet                  only print errors"
   , "  --help                   display this help and exit"
   , "  --version                output version information and exit"
   , "  --info                   output machine-readable version information and exit"
@@ -73,10 +76,18 @@
   , cfgVerbose :: Bool
   -- ^ Verbose output (default: @False@)
   , cfgModules :: [ModuleName]
-  -- ^ Module names to test
+  -- ^ Module names to test. An empty list means "test all modules".
   , cfgThreads :: Maybe Int
   -- ^ Number of threads to use. Defaults to autodetection based on the number
   -- of cores.
+  , cfgRandomizeOrder :: Bool
+  -- ^ Randomize the order in which test cases in a module are run (default: @False@)
+  , cfgSeed :: Maybe Int
+  -- ^ Initialize random number generator used to randomize test cases when
+  -- 'cfgRandomizeOrder' is set. If set to 'Nothing', a random seed is picked
+  -- from a system RNG source on startup.
+  , cfgQuiet :: Bool
+  -- ^ Only print error messages, no status or progress messages (default: @False@)
   } deriving (Show, Eq)
 
 defaultConfig :: Config
@@ -85,6 +96,9 @@
   , cfgVerbose = False
   , cfgModules = []
   , cfgThreads = Nothing
+  , cfgRandomizeOrder = False
+  , cfgSeed = Nothing
+  , cfgQuiet = False
   }
 
 parseOptions :: [String] -> Result Config
@@ -96,17 +110,57 @@
       "--help" -> ResultStdout usage
       "--info" -> ResultStdout info
       "--version" -> ResultStdout versionInfo
+      "--randomize-order" -> go config{cfgRandomizeOrder=True} args
       "--preserve-it" -> go config{cfgPreserveIt=True} args
       "--verbose" -> go config{cfgVerbose=True} args
-      ('-':'j':n0) | Just n1 <- parseThreads n0 -> go config{cfgThreads=Just n1} args
+      "--quiet" -> go config{cfgQuiet=True} args
+      ('-':_) | Just n <- parseSeed arg -> go config{cfgSeed=Just n} args
+      ('-':_) | Just n <- parseThreads arg -> go config{cfgThreads=Just n} args
       ('-':_) -> ResultStderr ("Unknown command line argument: " <> arg)
       mod_ -> go config{cfgModules=mod_ : cfgModules config} args
 
+-- | Parse seed argument
+--
+-- >>> parseSeed "--seed=6"
+-- Just 6
+-- >>> parseSeed "--seeeed=6"
+-- Nothing
+--
+parseSeed :: String -> Maybe Int
+parseSeed arg = readMaybe =<< parseSpecificFlag arg "seed"
+
+
+-- | Parse number of threads argument
+--
+-- >>> parseThreads "-j6"
+-- Just 6
+-- >>> parseThreads "-j-2"
+-- Nothing
+-- >>> parseThreads "-jA"
+-- Nothing
+--
 parseThreads :: String -> Maybe Int
-parseThreads n0 = do
+parseThreads ('-':'j':n0) = do
   n1 <- readMaybe n0
   if n1 > 0 then Just n1 else Nothing
+parseThreads _ = Nothing
 
+-- | Parse a specific flag with a value, or return 'Nothing'
+--
+-- >>> parseSpecificFlag "--foo" "foo"
+-- Nothing
+-- >>> parseSpecificFlag "--foo=" "foo"
+-- Nothing
+-- >>> parseSpecificFlag "--foo=5" "foo"
+-- Just "5"
+-- >>> parseSpecificFlag "--foo=5" "bar"
+-- Nothing
+parseSpecificFlag :: String -> String -> Maybe String
+parseSpecificFlag arg flag = do
+  case parseFlag arg of
+    ('-':'-':f, value) | f == flag -> value
+    _ -> Nothing
+
 -- | Parse a flag into its flag and argument component.
 --
 -- Example:
@@ -121,5 +175,5 @@
 parseFlag arg =
   case break (== '=') arg of
     (flag, ['=']) -> (flag, Nothing)
-    (flag, ('=':opt)) -> (flag, Just opt)
+    (flag, '=':opt) -> (flag, Just opt)
     (flag, _) -> (flag, Nothing)
diff --git a/src/Test/DocTest/Internal/Runner.hs b/src/Test/DocTest/Internal/Runner.hs
--- a/src/Test/DocTest/Internal/Runner.hs
+++ b/src/Test/DocTest/Internal/Runner.hs
@@ -1,5 +1,7 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE MultiWayIf #-}
+{-# LANGUAGE TypeApplications #-}
+{-# LANGUAGE NamedFieldPuns #-}
 
 module Test.DocTest.Internal.Runner where
 
@@ -8,11 +10,14 @@
 import           Control.Concurrent (Chan, writeChan, readChan, newChan, forkIO)
 import           Control.Exception (SomeException, catch)
 import           Control.Monad hiding (forM_)
-import           Data.Maybe (fromMaybe)
-import           Text.Printf (printf)
-import           System.IO (hPutStrLn, hPutStr, stderr, hIsTerminalDevice)
 import           Data.Foldable (forM_)
+import           Data.Function (on)
+import           Data.List (sortBy)
+import           Data.Maybe (fromMaybe)
 import           GHC.Conc (numCapabilities)
+import           System.IO (hPutStrLn, hPutStr, stderr, hIsTerminalDevice)
+import           System.Random (randoms, mkStdGen)
+import           Text.Printf (printf)
 
 import           Control.Monad.Trans.State
 import           Control.Monad.IO.Class
@@ -70,35 +75,46 @@
   -- ^ Preserve it
   -> Bool
   -- ^ Verbose
+  -> Maybe Int
+  -- ^ If 'Just', use seed to randomize test order
   -> Bool
   -- ^ Implicit Prelude
   -> [String]
   -- ^ Arguments passed to the GHCi process.
+  -> Bool
+  -- ^ Quiet mode activated
   -> [Module [Located DocTest]]
   -- ^ Modules under test
   -> IO Summary
-runModules nThreads preserveIt verbose implicitPrelude args modules = do
+runModules nThreads preserveIt verbose seed implicitPrelude args quiet modules = do
   isInteractive <- hIsTerminalDevice stderr
 
   -- Start a thread pool. It sends status updates to this thread through 'output'.
   (input, output) <-
     makeThreadPool
       (fromMaybe numCapabilities nThreads)
-      (runModule preserveIt implicitPrelude args)
+      (runModule preserveIt seed implicitPrelude args)
 
   -- Send instructions to threads
   liftIO (mapM_ (writeChan input) modules)
 
   let
     nExamples = (sum . map count) modules
-    initState = ReportState 0 isInteractive verbose mempty {sExamples = nExamples}
+    initState = ReportState
+      { reportStateCount = 0
+      , reportStateInteractive = isInteractive
+      , reportStateVerbose = verbose
+      , reportStateQuiet = quiet
+      , reportStateSummary = mempty{sExamples=nExamples}
+      }
 
-  ReportState _ _ _ s <- (`execStateT` initState) $ do
+  ReportState{reportStateSummary} <- (`execStateT` initState) $ do
     consumeUpdates output (length modules)
-    verboseReport "# Final summary:"
-    gets (show . reportStateSummary) >>= report
+    unless quiet $ do
+      verboseReport "# Final summary:"
+      gets (show . reportStateSummary) >>= report
 
-  return s
+  return reportStateSummary
  where
   consumeUpdates _output 0 = pure ()
   consumeUpdates output modsLeft = do
@@ -125,6 +141,7 @@
   reportStateCount        :: Int     -- ^ characters on the current line
 , reportStateInteractive  :: Bool    -- ^ should intermediate results be printed?
 , reportStateVerbose      :: Bool
+, reportStateQuiet        :: Bool
 , reportStateSummary      :: Summary -- ^ test summary
 }
 
@@ -156,15 +173,27 @@
           | otherwise = msg
   liftIO (hPutStr stderr str)
 
+-- | Shuffle a list given a seed for an RNG
+shuffle :: Int -> [a] -> [a]
+shuffle seed xs =
+    map snd
+  $ sortBy (compare `on` fst)
+  $ zip (randoms @Int (mkStdGen seed)) xs
+
 -- | Run all examples from given module.
 runModule
   :: Bool
+  -> Maybe Int
   -> Bool
   -> [String]
   -> Chan ReportUpdate
   -> Module [Located DocTest]
   -> IO ()
-runModule preserveIt implicitPrelude ghciArgs output (Module module_ setup examples) = do
+runModule preserveIt (Just seed) implicitPrelude ghciArgs output (Module module_ setup examples) = do
+  runModule
+    preserveIt Nothing implicitPrelude ghciArgs output
+    (Module module_ setup (shuffle seed examples))
+runModule preserveIt Nothing implicitPrelude ghciArgs output (Module module_ setup examples) = do
   Interpreter.withInterpreter ghciArgs $ \repl -> withCP65001 $ do
     -- Try to import this module, if it fails, something is off
     importResult <- Interpreter.safeEval repl importModule
@@ -242,7 +271,10 @@
 
 reportStart :: Location -> Expression -> String -> Report ()
 reportStart loc expression testType = do
-  verboseReport (printf "### Started execution at %s.\n### %s:\n%s" (show loc) testType expression)
+  quiet <- gets reportStateQuiet
+  unless quiet $
+    verboseReport
+      (printf "### Started execution at %s.\n### %s:\n%s" (show loc) testType expression)
 
 reportFailure :: FromSetup -> Location -> Expression -> [String] -> Report ()
 reportFailure fromSetup loc expression err = do
@@ -275,33 +307,46 @@
   report "   * Run with '--write-ghc-environment-files=always'"
   report "   * Add 'write-ghc-environment-files: always' to your cabal.project"
   report ""
-  report " 3. The testsuite executable does not have a dependency on your project library. Please add it to the 'build-depends' section of the testsuite executable."
+  report " 3. For Cabal users: Cabal did not generate a GHC environment file in time. This"
+  report "    can happen if you use 'cabal test' instead of 'cabal run doctests'. See"
+  report "    https://github.com/martijnbastiaan/doctest-parallel/issues/22."
   report ""
-  report "See the example project at https://github.com/martijnbastiaan/doctest-parallel/tree/master/examples for more information."
+  report " 4. The testsuite executable does not have a dependency on your project library. Please"
+  report "    add it to the 'build-depends' section of the testsuite executable."
+  report ""
+  report "See the example project at https://github.com/martijnbastiaan/doctest-parallel/blob/main/example/README.md for more information."
   updateSummary FromSetup emptySummary{sErrors=1}
 
 reportSuccess :: FromSetup -> Location -> Report ()
 reportSuccess fromSetup loc = do
-  verboseReport (printf "### Successful `%s'!\n" (show loc))
+  quiet <- gets reportStateQuiet
+  unless quiet $
+    verboseReport (printf "### Successful `%s'!\n" (show loc))
   updateSummary fromSetup (Summary 0 1 0 0)
 
 verboseReport :: String -> Report ()
 verboseReport xs = do
   verbose <- gets reportStateVerbose
-  when verbose $ report xs
+  quiet <- gets reportStateQuiet
+  unless quiet $
+    when verbose $
+      report xs
 
 updateSummary :: FromSetup -> Summary -> Report ()
 updateSummary FromSetup summary =
   -- Suppress counts, except for errors
   updateSummary NotFromSetup summary{sExamples=0, sTried=0, sFailures=0}
 updateSummary NotFromSetup summary = do
-  ReportState n f v s <- get
-  put (ReportState n f v $ s `mappend` summary)
+  ReportState n f v q s <- get
+  put (ReportState n f v q $ s `mappend` summary)
 
 reportProgress :: Report ()
 reportProgress = do
   verbose <- gets reportStateVerbose
-  when (not verbose) $ gets (show . reportStateSummary) >>= report_
+  quiet <- gets reportStateQuiet
+  unless quiet $
+    unless verbose $
+      gets (show . reportStateSummary) >>= report_
 
 -- | Run given test group.
 --
diff --git a/test/MainSpec.hs b/test/MainSpec.hs
--- a/test/MainSpec.hs
+++ b/test/MainSpec.hs
@@ -7,10 +7,12 @@
 import           Test.Hspec
 import           Test.HUnit (assertEqual, Assertion)
 
+import qualified Data.Map as Map
 import qualified Test.DocTest as DocTest
 import           Test.DocTest.Helpers (extractSpecificCabalLibrary, findCabalPackage)
 import           Test.DocTest.Internal.Options
 import           Test.DocTest.Internal.Runner
+import           System.Environment (getEnvironment)
 import           System.IO.Silently
 import           System.IO
 
@@ -24,7 +26,7 @@
   lib <- extractSpecificCabalLibrary (Just "spectests-modules") pkg
   actual <-
     hSilence [stderr] $
-      DocTest.main lib config{cfgModules=modNames}
+      DocTest.run lib config{cfgModules=modNames}
   assertEqual (show modNames) expected actual
 
 cases :: Int -> Summary
@@ -35,7 +37,17 @@
 
 spec :: Spec
 spec = do
-  describe "doctest" $ do
+  env <- runIO getEnvironment
+  let
+    cDescribe =
+      -- Don't run doctests as part of the Stack testsuite yet, pending
+      -- https://github.com/commercialhaskell/stack/issues/5662
+      if "STACK_EXE" `Map.member` Map.fromList env then
+        xdescribe
+      else
+        describe
+
+  cDescribe "doctest" $ do
     it "testSimple" $
       doctest ["TestSimple.Fib"]
         (cases 1)
@@ -109,7 +121,7 @@
       doctest ["TrailingWhitespace.Foo"]
         (cases 1)
 
-  describe "doctest as a runner for QuickCheck properties" $ do
+  cDescribe "doctest as a runner for QuickCheck properties" $ do
     it "runs a boolean property" $ do
       doctest ["PropertyBool.Foo"]
         (cases 1)
@@ -134,12 +146,12 @@
       doctest ["PropertySetup.Foo"]
         (cases 1)
 
-  describe "doctest (module isolation)" $ do
+  cDescribe "doctest (module isolation)" $ do
     it "should fail due to module isolation" $ do
       doctestWithOpts defaultConfig ["ModuleIsolation.TestA", "ModuleIsolation.TestB"]
         (cases 2) {sFailures = 1}
 
-  describe "doctest (regression tests)" $ do
+  cDescribe "doctest (regression tests)" $ do
     it "bugfixOutputToStdErr" $ do
       doctest ["BugfixOutputToStdErr.Fib"]
         (cases 2)
@@ -160,3 +172,7 @@
     it "doesn't get confused by doctests using System.IO imports" $ do
       doctest ["SystemIoImported.A"]
         (cases 2)
+
+    it "correctly handles C import directories" $ do
+      doctest ["WithCInclude.Bar"]
+        (cases 1)
diff --git a/test/RunnerSpec.hs b/test/RunnerSpec.hs
--- a/test/RunnerSpec.hs
+++ b/test/RunnerSpec.hs
@@ -12,11 +12,11 @@
 main = hspec spec
 
 capture :: Report a -> IO String
-capture = fmap fst . hCapture [stderr] . (`execStateT` ReportState 0 True False mempty)
+capture = fmap fst . hCapture [stderr] . (`execStateT` ReportState 0 True False False mempty)
 
 -- like capture, but with interactivity set to False
 capture_ :: Report a -> IO String
-capture_ = fmap fst . hCapture [stderr] . (`execStateT` ReportState 0 False False mempty)
+capture_ = fmap fst . hCapture [stderr] . (`execStateT` ReportState 0 False False False mempty)
 
 spec :: Spec
 spec = do
diff --git a/test/doctests.hs b/test/doctests.hs
--- a/test/doctests.hs
+++ b/test/doctests.hs
@@ -4,4 +4,6 @@
 import System.Environment (getArgs)
 
 main :: IO ()
-main = mainFromCabal "doctest-parallel" =<< getArgs
+main = do
+  args <- getArgs
+  mainFromCabal "doctest-parallel" ("--randomize-order":args)
diff --git a/test/integration/WithCInclude/Bar.hs b/test/integration/WithCInclude/Bar.hs
new file mode 100644
--- /dev/null
+++ b/test/integration/WithCInclude/Bar.hs
@@ -0,0 +1,12 @@
+{-# LANGUAGE CPP #-}
+
+module WithCInclude.Bar where
+
+#include "WithCInclude.h"
+
+
+-- |
+-- >>> x
+-- 42
+x :: Int
+x = THE_DEFINE
diff --git a/test/integration/WithCInclude/include/WithCInclude.h b/test/integration/WithCInclude/include/WithCInclude.h
new file mode 100644
--- /dev/null
+++ b/test/integration/WithCInclude/include/WithCInclude.h
@@ -0,0 +1,1 @@
+#define THE_DEFINE 42