diff --git a/autonix-deps.cabal b/autonix-deps.cabal
--- a/autonix-deps.cabal
+++ b/autonix-deps.cabal
@@ -1,5 +1,5 @@
 name:                autonix-deps
-version:             0.1.0.1
+version:             0.2.0.0
 synopsis:            Library for Nix expression dependency generation
 license:             BSD3
 license-file:        LICENSE
diff --git a/src/Autonix/Analyze.hs b/src/Autonix/Analyze.hs
--- a/src/Autonix/Analyze.hs
+++ b/src/Autonix/Analyze.hs
@@ -25,11 +25,9 @@
 
 analyzePackages :: (MonadIO m, MonadState Deps m)
                 => (ByteString -> FilePath -> m a)
-                -> FilePath -> Maybe FilePath -> m ()
-analyzePackages perPackage manifestPath renamesPath = do
+                -> FilePath -> m ()
+analyzePackages perPackage manifestPath = do
     manifest <- readManifest manifestPath
-    renames <- readRenames renamesPath
-    names %= flip M.union renames
     forM_ manifest $ \(pkg, _) -> at pkg .= Just mempty
     let (pkgs, _) = unzip manifest
     mapM_ (uncurry perPackage) manifest
diff --git a/src/Autonix/Args.hs b/src/Autonix/Args.hs
--- a/src/Autonix/Args.hs
+++ b/src/Autonix/Args.hs
@@ -5,12 +5,8 @@
 import Control.Monad.IO.Class
 import Options.Applicative
 
-withArgs :: MonadIO m => (FilePath -> Maybe FilePath -> m a) -> m a
+withArgs :: MonadIO m => (FilePath -> m a) -> m a
 withArgs child =
     join $ liftIO $ execParser $ info (helper <*> parser) fullDesc
   where
-    parser = child
-             <$> strArgument (metavar "MANIFEST")
-             <*> option
-                (Just <$> str)
-                (long "renames" <> metavar "FILENAME" <> value Nothing)
+    parser = child <$> strArgument (metavar "MANIFEST")
diff --git a/src/Autonix/Deps.hs b/src/Autonix/Deps.hs
--- a/src/Autonix/Deps.hs
+++ b/src/Autonix/Deps.hs
@@ -13,11 +13,8 @@
 
 import Control.Lens
 import Control.Monad.State
-import qualified Data.ByteString.Char8 as B
-import qualified Data.Char as Char
 import qualified Data.Map as M
 import Data.Monoid
-import qualified Data.Set as S
 import Prelude hiding (foldr)
 
 import Autonix.PkgDeps
@@ -33,50 +30,19 @@
     mempty = Deps { _names = M.empty, _deps = M.empty }
 
     mappend a b = flip execState a $ do
-        let b' = execState (iforMOf_ (names.>itraversed) a rename) b
-        iforMOf_ (names.>itraversed) b' rename
-        names %= M.union (b'^.names)
-        deps %= M.unionWith mappend (b'^.deps)
-
-lookupNewName :: Deps -> ByteString -> ByteString
-lookupNewName r (B.map Char.toLower -> idx) =
-  M.findWithDefault idx idx (r^.names)
-
-renamePkgDeps :: ByteString -> ByteString -> PkgDeps -> PkgDeps
-renamePkgDeps old new =
-  execState $ do
-    buildInputs %= S.map go
-    nativeBuildInputs %= S.map go
-    propagatedBuildInputs %= S.map go
-    propagatedNativeBuildInputs %= S.map go
-    propagatedUserEnvPkgs %= S.map go
-  where
-    go pkg | pkg == old = new
-           | otherwise = pkg
+      let b' = execState (iforMOf_ (names.>itraversed) a rename) b
+      iforMOf_ (names.>itraversed) b' rename
+      names %= M.union (b'^.names)
+      deps %= M.unionWith mappend (b'^.deps)
 
 rename :: (MonadState Deps m) => ByteString -> ByteString -> m ()
-rename (B.map Char.toLower -> old) (B.map Char.toLower -> new) = do
-    names %= M.insert old new
-    names %= M.map (\tgt -> if tgt == old then new else tgt)
-    deps %= M.map (renamePkgDeps old new)
-    ds <- get
-    deps %= M.mapKeysWith mappend (lookupNewName ds)
-
-applyRenames :: Deps -> PkgDeps -> PkgDeps
-applyRenames r = execState $ do
-    buildInputs %= S.map (lookupNewName r)
-    propagatedBuildInputs %= S.map (lookupNewName r)
-    nativeBuildInputs %= S.map (lookupNewName r)
-    propagatedNativeBuildInputs %= S.map (lookupNewName r)
-    propagatedUserEnvPkgs %= S.map (lookupNewName r)
+rename old new = names %= M.insert old new
 
 type instance Index Deps = ByteString
 type instance IxValue Deps = PkgDeps
 
 instance Ixed Deps where
-    ix idx f r =
-        (deps . ix (lookupNewName r idx)) (fmap (applyRenames r) . f) r
+    ix idx = deps . ix idx
 
 instance At Deps where
-    at idx f r =
-        (deps . at (lookupNewName r idx)) (fmap (fmap $ applyRenames r) . f) r
+    at idx = deps . at idx
diff --git a/src/Autonix/Generate.hs b/src/Autonix/Generate.hs
--- a/src/Autonix/Generate.hs
+++ b/src/Autonix/Generate.hs
@@ -29,11 +29,19 @@
 writeDeps = liftIO . B.writeFile "dependencies.nix" . depsToNix
 
 writeRenames :: MonadIO m => Deps -> m ()
-writeRenames ds = do
-    let renames = B.unlines $ do
-            (old, new) <- M.toList (ds^.names)
-            return $ old <> " " <> new
-    liftIO $ B.writeFile "renames.txt" renames
+writeRenames ds = liftIO $ do
+  let renames = do
+        (old, new) <- M.toList (ds^.names)
+        return ("\"" <> old <> "\" = \"" <> new <> "\";")
+  B.writeFile
+    "renames.nix"
+    (B.unlines
+      ([ "# DO NOT EDIT! This file is generated automatically."
+       , "{ }:"
+       , "{"
+       ]
+       ++ renames ++
+       [ "}" ]))
 
 packageDeps :: (ByteString, PkgDeps) -> ByteString
 packageDeps (name, ds) =