diff --git a/Main.hs b/Main.hs
--- a/Main.hs
+++ b/Main.hs
@@ -17,6 +17,7 @@
 import Control.Error
 
 import qualified Data.ByteString.Char8 as BS
+import System.IO.Temp
 
 import Distribution.Verbosity (Verbosity, normal)
 import Distribution.Simple.Compiler (Compiler (compilerId), compilerFlavor)
@@ -33,16 +34,16 @@
 import qualified Distribution.Simple.InstallDirs as IDirs
 
 -- | Various configuration
-data Config = Config { outputDir       :: FilePath
-                     , verbosity       :: Verbosity
-                     , installTextBase :: Bool
-                     , useLocalDocs    :: Bool
+data Config = Config { verbosity               :: Verbosity
+                     , installTextBase         :: Bool
+                     , useLocalDocs            :: Bool
+                     , ignoreExistingTextBases :: Bool
                      }
 
-config = Config { outputDir       = "./hoogle-index"
-                , verbosity       = normal
-                , installTextBase = True
-                , useLocalDocs    = True
+config = Config { verbosity               = normal
+                , installTextBase         = True
+                , useLocalDocs            = True
+                , ignoreExistingTextBases = False
                 }
 
 -- | An unpacked Cabal project
@@ -60,14 +61,17 @@
       ExitFailure e -> left $ "Process "++exec++" failed with error "++show e
 
 -- | Unpack a package
-unpack :: PackageId -> IO PackageTree
+unpack :: PackageId -> EitherT String IO PackageTree
 unpack (PackageIdentifier (PackageName pkg) ver) = do
-    callProcess "cabal" ["unpack", pkg++"=="++showVersion ver]
-    return $ PkgTree $ pkg++"-"++showVersion ver
+    tmpDir <- liftIO getTemporaryDirectory
+    dir <- liftIO $ createTempDirectory tmpDir "hoogle-index.pkg"
+    callProcessIn dir "cabal" ["unpack", pkg++"=="++showVersion ver]
+    return $ PkgTree $ dir </> pkg++"-"++showVersion ver
 
 -- | Remove an unpacked tree
 removeTree :: PackageTree -> IO ()
-removeTree (PkgTree dir) = removeDirectoryRecursive dir
+removeTree (PkgTree dir) =
+    removeDirectoryRecursive $ takeDirectory dir
 
 -- | A Haddock textbase
 newtype TextBase = TextBase BS.ByteString
@@ -103,11 +107,13 @@
 
 getTextBase :: Config -> InstalledPackageInfo -> EitherT String IO TextBase
 getTextBase cfg ipkg = do
-    existing <- liftIO $ findTextBase ipkg
+    existing <- if ignoreExistingTextBases cfg
+                  then return Nothing
+                  else liftIO $ findTextBase ipkg
     case existing of
       Just path -> TextBase <$> liftIO (BS.readFile path)
       Nothing -> do
-        pkgTree <- fmapLT show $ tryIO $ unpack pkg
+        pkgTree <- unpack pkg
         tb <- buildTextBase (pkgName pkg) pkgTree
         liftIO $ removeTree pkgTree
 
@@ -127,14 +133,21 @@
 newtype Database = DB FilePath
                  deriving (Show)
 
+-- | Delete a database file
+removeDB :: Database -> IO ()
+removeDB (DB path) = removeFile path
+
 -- | Convert a textbase to a Hoogle database
 convert :: TextBaseFile -> Maybe FilePath -> [Database] -> EitherT String IO Database
 convert tbf docRoot merge = do
     let docRoot' = maybe [] (\d->["--haddock", "--doc="++d]) docRoot
-    let args = ["convert", tbf] ++ docRoot'
+    (tb,h) <- liftIO $ openTempFile "/tmp" "db.hoo"
+    liftIO $ hClose h
+    let args = ["convert", tbf, tb] ++ docRoot'
                ++ map (\(DB db)->"--merge="++db) merge
+
     fmapLT show $ tryIO $ callProcess "hoogle" args
-    return $ DB $ replaceExtension tbf ".hoo"
+    return $ DB tb
 
 -- | Generate a Hoogle database for an installed package
 indexPackage :: Config -> InstalledPackageInfo -> EitherT String IO Database
@@ -142,9 +155,9 @@
     let pkg = sourcePackageId ipkg
     tb <- getTextBase cfg ipkg
     docRoot <- case haddockHTMLs ipkg of
-                   docRoot:_ | useLocalDocs cfg -> Just docRoot 
+                   docRoot:_ | useLocalDocs cfg -> return $ Just docRoot
                    []        | useLocalDocs cfg -> do
-                     putStrLn $ "No local documentation for "++pkg
+                     liftIO $ putStrLn $ "No local documentation for "++show pkg
                      return Nothing
                    _ -> return Nothing
     (tbf,h) <- liftIO $ openTempFile "/tmp" "textbase.txt"
@@ -157,7 +170,9 @@
 -- | Combine Hoogle databases
 combineDBs :: [Database] -> IO Database
 combineDBs dbs = do
-    let out = "all.hoo"
+    tmpDir <- getTemporaryDirectory
+    (out, h) <- openTempFile tmpDir "combined.hoo"
+    hClose h
     callProcess "hoogle" (["combine", "--outfile="++out] ++ map (\(DB db)->db) dbs)
     return (DB out)
 
@@ -180,7 +195,6 @@
 
 main :: IO ()
 main = do
-    createDirectoryIfMissing True (outputDir config)
     (compiler, _, progCfg) <- configure (verbosity config)
                               Nothing Nothing
                               defaultProgramConfiguration
@@ -198,5 +212,6 @@
       putStrLn $ unlines $ map failedMsg failed
 
     combined <- combineDBs idxs
+    --mapM_ removeDB idxs
     res <- runEitherT $ installDB compiler pkgIdx combined
     either print (const $ return ()) res
diff --git a/hoogle-index.cabal b/hoogle-index.cabal
--- a/hoogle-index.cabal
+++ b/hoogle-index.cabal
@@ -1,5 +1,5 @@
 name:                hoogle-index
-version:             0.1
+version:             0.2
 synopsis:            Easily generate Hoogle indices for installed packages
 description:         Easily generate Hoogle indices for installed packages
 homepage:            http://github.com/bgamari/hoogle-index
@@ -26,5 +26,6 @@
                        filepath >=1.3 && <1.4,
                        errors >=1.4 && <1.5,
                        bytestring >=0.9 && <1.11,
+                       temporary >=1.2 && <1.3,
                        Cabal >=1.20 && <1.21
   default-language:    Haskell2010