diff --git a/shake-ext.cabal b/shake-ext.cabal
--- a/shake-ext.cabal
+++ b/shake-ext.cabal
@@ -1,5 +1,5 @@
 name:                shake-ext
-version:             1.1.0.0
+version:             1.2.0.0
 synopsis:            Helper functions for linting with shake 
 description:         This package provides several linters out of the box, as well as functionality for building ATS source files with [shake](http://shakebuild.com/).
 homepage:            https://hub.darcs.net/vmchale/shake-ext
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
@@ -32,14 +32,14 @@
     show (Version [x])    = show x
     show (Version (x:xs)) = show x ++ "." ++ show (Version xs)
 
-patsHome :: Action String
-patsHome = fromMaybe "/usr/local/lib/ats2-postiats-0.3.9" <$> mh
-    where mh = fmap (++ "/.atspkg/0.3.8/") <$> getEnv "HOME"
+patsHome :: Version -> Action String
+patsHome v = fromMaybe "/usr/local/lib/ats2-postiats-0.3.9" <$> mh
+    where mh = fmap (++ ("/.atspkg/" ++ show v ++ "/")) <$> getEnv "HOME"
 
 -- TODO install the whole compiler?
-atsCommand :: CmdResult r => Version -> String -> String -> Action r
-atsCommand v sourceFile out = do
-    h <- patsHome
+atsCommand :: CmdResult r => Version -> Version -> String -> String -> Action r
+atsCommand v v' sourceFile out = do
+    h <- patsHome v'
     let home = h ++ "lib/ats2-postiats-" ++ show v
     let atsArgs = [EchoStderr False, AddEnv "PATSHOME" home]
         patsc = "patsopt"
@@ -49,24 +49,24 @@
 gcFlag False = "-DATS_MEMALLOC_LIBC"
 gcFlag True  = "-DATS_MEMALLOC_GCBDW"
 
-copySources :: Version -> [FilePath] -> Action ()
-copySources v sources =
+copySources :: Version -> Version -> [FilePath] -> Action ()
+copySources v v' sources =
     forM_ sources $ \dep -> do
-        h <- patsHome
+        h <- patsHome v'
         let home = h ++ "lib/ats2-postiats-" ++ show v
         liftIO $ createDirectoryIfMissing True (home ++ "/" ++ takeDirectory dep)
         liftIO $ copyFile dep (home ++ "/" ++ dep)
 
 -- TODO musl?
-atsBin :: Version -> Bool -> [String] -> String -> String -> Rules ()
-atsBin v gc libs sourceFile out =
+atsBin :: Version -> Version -> Bool -> [String] -> String -> String -> Rules ()
+atsBin v v' gc libs sourceFile out =
 
     out %> \_ -> do
         sources <- transitiveDeps [sourceFile]
-        h <- patsHome
+        h <- patsHome v'
         let home = h ++ "lib/ats2-postiats-" ++ show v
         need sources
-        copySources v sources
+        copySources v v' sources
         cmd_ ["mkdir", "-p", dropDirectory1 out]
 
         let toLibs = fmap ("-l" <>)
@@ -93,11 +93,11 @@
         removeFilesAfter ".atspkg" ["//*"]
         removeFilesAfter "ats-deps" ["//*"]
 
-handleSource :: Version -> FilePath -> Action ()
-handleSource v sourceFile = do
+handleSource :: Version -> Version -> FilePath -> Action ()
+handleSource v v' sourceFile = do
         sources <- transitiveDeps [sourceFile]
         need sources
-        copySources v sources
+        copySources v v' sources
 
 -- | This provides rules for generating C code from ATS source files in the
 -- @ats-src@ directory.
@@ -106,8 +106,8 @@
 
     "//*.c" %> \out -> do
         let sourceFile = dir ++ "/" ++ (dropDirectory1 out -<.> "dats")
-        handleSource v sourceFile
-        atsCommand v sourceFile out
+        handleSource v v sourceFile
+        atsCommand v v sourceFile out
 
 trim :: String -> String
 trim = init . drop 1
@@ -128,8 +128,8 @@
     "//*.c" %> \out -> do
 
         let sourceFile = dir ++ "/" ++ (dropDirectory1 out -<.> "dats")
-        handleSource v sourceFile
-        (Exit c, Stderr err) :: (Exit, Stderr String) <- atsCommand v sourceFile out
+        handleSource v v sourceFile
+        (Exit c, Stderr err) :: (Exit, Stderr String) <- atsCommand v v sourceFile out
         cmd_ [Stdin err] Shell "pats-filter"
         if c /= ExitSuccess
             then error "patscc failure"
diff --git a/src/Development/Shake/C.hs b/src/Development/Shake/C.hs
--- a/src/Development/Shake/C.hs
+++ b/src/Development/Shake/C.hs
@@ -5,10 +5,10 @@
 import           Development.Shake.ATS
 
 -- | Build a C binary, including relevant ATS-related paths.
-cBinary :: FilePath -> FilePath -> Action ()
-cBinary src target = do
+cBinary :: Version -> FilePath -> FilePath -> Action ()
+cBinary v src target = do
     need [src]
-    home <- patsHome
+    home <- patsHome v
     let atsArgs = [EchoStderr False, AddEnv "PATSHOME" home]
     command atsArgs "gcc" [src, "-flto", "-I" ++ home ++ "/ccomp/runtime", "-I" ++ home, "-o", target, "-O2"]
         -- cmd ["strip", out]