diff --git a/shake-ats.cabal b/shake-ats.cabal
--- a/shake-ats.cabal
+++ b/shake-ats.cabal
@@ -1,6 +1,6 @@
 cabal-version: 1.18
 name: shake-ats
-version: 1.8.0.4
+version: 1.8.0.5
 license: BSD3
 license-file: LICENSE
 copyright: Copyright: (c) 2018 Vanessa McHale
@@ -44,7 +44,8 @@
         shake-ext >=2.9.0.0,
         hs2ats >=0.2.0.1,
         directory -any,
-        lens -any,
+        microlens -any,
+        microlens-th -any,
         text -any,
         dependency -any,
         shake -any,
diff --git a/src/Development/Shake/ATS.hs b/src/Development/Shake/ATS.hs
--- a/src/Development/Shake/ATS.hs
+++ b/src/Development/Shake/ATS.hs
@@ -53,11 +53,11 @@
                              ) where
 
 import           Control.Arrow
-import           Control.Lens
 import           Control.Monad
 import           Control.Monad.IO.Class
 import           Data.Bool                         (bool)
 import           Data.Either                       (fromRight)
+import           Data.Foldable                     (fold)
 import           Data.Maybe                        (fromMaybe)
 import           Data.Semigroup                    (Semigroup (..))
 import qualified Data.Text.Lazy                    as TL
@@ -69,6 +69,7 @@
 import           Development.Shake.FilePath
 import           Development.Shake.Version
 import           Language.ATS
+import           Lens.Micro
 import           System.Directory                  (copyFile, createDirectoryIfMissing, doesFileExist)
 import           System.Environment                (getEnv)
 import           System.Exit                       (ExitCode (ExitSuccess))
@@ -142,7 +143,6 @@
         cc' = _cc tc
         f = bool id ("atslib":) (_linkATSLib tc)
     h' <- pkgHome cc'
-    -- FIXME only bother with atslib if it's unnecessary?
     let libs'' = f $ bool libs' ("gc" : libs') gc'
     pure $ CConfig [h ++ "/ccomp/runtime/", h, h' ++ "include", ".atspkg/contrib"] libs'' [h' ++ "lib", _patsHome tc ++ "/ccomp/atslib/lib"] extras (_linkStatic tc)
 
@@ -245,10 +245,10 @@
 
 transitiveDeps :: (MonadIO m) => [FilePath] -> [FilePath] -> m [FilePath]
 transitiveDeps _ [] = pure []
-transitiveDeps gen ps = fmap join $ forM ps $ \p -> if p `elem` gen then pure mempty else do
+transitiveDeps gen ps = fmap fold $ forM ps $ \p -> if p `elem` gen then pure mempty else do
     contents <- liftIO $ readFile p
-    let (ats, err) = (fromRight mempty &&& maybeError p) . parseM $ contents
-    err
+    let (ats, err) = (fromRight mempty &&& id) . parseM $ contents
+    maybeError p err
     let dir = takeDirectory p
     deps <- filterM (\f -> ((f `elem` gen) ||) <$> (liftIO . doesFileExist) f) $ fixDir dir . trim <$> getDependencies ats
     deps' <- transitiveDeps gen deps
diff --git a/src/Development/Shake/ATS/Generate.hs b/src/Development/Shake/ATS/Generate.hs
--- a/src/Development/Shake/ATS/Generate.hs
+++ b/src/Development/Shake/ATS/Generate.hs
@@ -1,8 +1,8 @@
 module Development.Shake.ATS.Generate ( generateLinks
                                       ) where
 
-import           Control.Lens
 import           Language.ATS
+import           Lens.Micro
 
 generateLinks :: String -> Either ATSError String
 generateLinks = fmap (printATS . generateLinks') . parseM
diff --git a/src/Development/Shake/ATS/Type.hs b/src/Development/Shake/ATS/Type.hs
--- a/src/Development/Shake/ATS/Type.hs
+++ b/src/Development/Shake/ATS/Type.hs
@@ -37,13 +37,13 @@
                                   , patsFlags
                                   ) where
 
-import           Control.Lens
 import           Data.Binary         (Binary (..))
 import           Data.Dependency     (Version (..))
 import           Data.Hashable       (Hashable)
 import qualified Data.Text.Lazy      as TL
 import           Development.Shake.C
 import           GHC.Generics        (Generic)
+import           Lens.Micro.TH
 
 -- We should have four build types:
 --
@@ -90,7 +90,7 @@
                                    , _linkStatic   :: Bool -- ^ Force static linking
                                    , _solver       :: Solver
                                    , _linkATSLib   :: Bool -- ^ Whether to link against atslib
-                                   , _patsFlags :: [String] -- ^ Additional flags to pass to @patsopt@.
+                                   , _patsFlags    :: [String] -- ^ Additional flags to pass to @patsopt@.
                                    } deriving (Generic, Binary)
 
 data HATSGen = HATSGen { satsFile :: FilePath -- ^ @.sats@ file containing type definitions