diff --git a/ats-setup.cabal b/ats-setup.cabal
--- a/ats-setup.cabal
+++ b/ats-setup.cabal
@@ -1,5 +1,5 @@
 name:                ats-setup
-version:             0.3.1.1
+version:             0.4.0.0
 synopsis:            ATS scripts for Cabal builds
 description:         This package contains various scripts that go in a package's @Setup.hs@ to make building libraries with ATS dependencies easier.
 license:             BSD3
diff --git a/src/Distribution/ATS.hs b/src/Distribution/ATS.hs
--- a/src/Distribution/ATS.hs
+++ b/src/Distribution/ATS.hs
@@ -60,11 +60,13 @@
 setupCompiler' :: IO ()
 setupCompiler' = setupCompiler (Just "ats-deps") defV
 
+-- preConf :: Args -> ConfigFlags -> IO HookedBuildInfo
+
 -- | This generates user hooks for a Cabal distribution that has some ATS
 -- library dependencies. For an example of its use, see the @Setup.hs@ of
 -- [fast-arithmetic](https://hackage.haskell.org/package/fast-arithmetic)
 atsUserHooks :: [ATSDependency] -> UserHooks
-atsUserHooks deps = simpleUserHooks { preConf = \_ _ -> fetchDependencies deps >> pure emptyHookedBuildInfo
+atsUserHooks deps = simpleUserHooks { preConf = \_ flags -> fetchDependencies flags deps >> pure emptyHookedBuildInfo
                                     , postBuild = \_ _ _ -> maybeCleanBuild
                                     }
 
@@ -77,7 +79,7 @@
 
 -- | Same as 'atsUserHooks', but installs @atslib@ as well.
 atsLibUserHooks :: [ATSDependency] -> UserHooks
-atsLibUserHooks deps = simpleUserHooks { preConf = \_ _ -> mconcat [ installCompiler, fetchDependencies deps ] >> pure emptyHookedBuildInfo
+atsLibUserHooks deps = simpleUserHooks { preConf = \_ flags -> mconcat [ installCompiler, fetchDependencies flags deps ] >> pure emptyHookedBuildInfo
                                        , postBuild = \_ _ _ -> maybeCleanBuild
                                        }
 -- TODO custom directory?
@@ -106,8 +108,12 @@
 atsPrelude v = ATSDependency ("ats2-postiats-" ++ vs ++ "-prelude") "ats-deps/prelude" ("https://downloads.sourceforge.net/project/ats2-lang/ats2-lang/ats2-postiats-" ++ vs ++ "/ATS2-Postiats-include-" ++ vs ++ ".tgz")
     where vs = vString v
 
-fetchDependencies :: [ATSDependency] -> IO ()
-fetchDependencies = (>> stopGlobalPool) . parallel_ . fmap fetchDependency
+fetchDependencies :: ConfigFlags -> [ATSDependency] -> IO ()
+fetchDependencies cfs =
+    bool nothing act cond
+    where act = (>> stopGlobalPool) . parallel_ . fmap fetchDependency
+          nothing = pure $ pure ()
+          cond = (mkFlagName "with-atsdeps", True) `elem` configConfigurationsFlags cfs
 
 fetchDependency :: ATSDependency -> IO ()
 fetchDependency (ATSDependency libNameATS dirName url) = do