diff --git a/.gitignore b/.gitignore
index 849ddff..0d2ac34 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 dist/
+elisp/*.elc
diff --git a/CabalDev.hs b/CabalDev.hs
new file mode 100644
index 0000000..1e4be52
--- /dev/null
+++ b/CabalDev.hs
@@ -0,0 +1,45 @@
+{-# LANGUAGE DoAndIfThenElse #-}
+
+module CabalDev (modifyOptions) where
+
+{-
+If the directory 'cabal-dev/packages-X.X.X.conf' exists, add it to the
+options ghc-mod uses to check the source.  Otherwise just pass it on.
+-}
+
+import Data.Maybe             (listToMaybe)
+import System.FilePath.Find
+import System.FilePath.Posix  (splitPath,joinPath)
+import System.Posix.Directory (getWorkingDirectory)
+import System.Directory
+
+import Types
+
+modifyOptions :: Options -> IO Options
+modifyOptions opts =
+  fmap (has_cdev opts) findCabalDev
+ where
+  has_cdev :: Options -> Maybe String -> Options
+  has_cdev op Nothing = op
+  has_cdev op (Just path) = addPath op path
+
+findCabalDev :: IO (Maybe String)
+findCabalDev =
+  getWorkingDirectory >>= searchIt . splitPath
+
+addPath :: Options -> String -> Options
+addPath orig_opts path = do
+  let orig_paths = packageConfs orig_opts
+  orig_opts { packageConfs = orig_paths ++ [path] }
+
+searchIt :: [FilePath] -> IO (Maybe FilePath)
+searchIt [] = return Nothing
+searchIt path = do
+  a <- doesDirectoryExist (mpath path)
+  if a then do
+    b <- find always (fileName ~~? "packages*.conf") $ mpath path
+    maybe (searchIt $ init path) (return . Just) $ listToMaybe b
+  else
+    return Nothing
+  where
+    mpath a = joinPath a ++ "cabal-dev/"
diff --git a/Check.hs b/Check.hs
index 37189a1..66fa9bd 100644
--- a/Check.hs
+++ b/Check.hs
@@ -1,6 +1,7 @@
 module Check (checkSyntax) where
 
 import Cabal
+import CabalDev (modifyOptions)
 import Control.Applicative
 import CoreMonad
 import ErrMsg
@@ -12,7 +13,9 @@ import Types
 ----------------------------------------------------------------
 
 checkSyntax :: Options -> String -> IO String
-checkSyntax opt file = unlines <$> check opt file
+checkSyntax opt file = do
+  opt' <- modifyOptions opt
+  unlines <$> check opt' file
 
 ----------------------------------------------------------------
 
diff --git a/GHCMod.hs b/GHCMod.hs
index 3054afb..3d207b7 100644
--- a/GHCMod.hs
+++ b/GHCMod.hs
@@ -21,7 +21,7 @@ import Types
 ----------------------------------------------------------------
 
 usage :: String
-usage =    "ghc-mod version 0.6.2\n"
+usage =    "ghc-mod version 1.0.0\n"
         ++ "Usage:\n"
         ++ "\t ghc-mod list [-l]\n"
         ++ "\t ghc-mod lang [-l]\n"
@@ -51,10 +51,10 @@ argspec = [ Option "l" ["tolisp"]
             "print as a list of Lisp"
           , Option "h" ["hlintOpt"]
             (ReqArg (\h opts -> opts { hlintOpts = h : hlintOpts opts }) "hlintOpt")
-            "hint to be ignored"
+            "hlint options"
           , Option "g" ["ghcOpt"]
             (ReqArg (\g opts -> opts { ghcOpts = g : ghcOpts opts }) "ghcOpt")
-            "extra GHC options"
+            "GHC options"
           , Option "o" ["operators"]
             (NoArg (\opts -> opts { operators = True }))
             "print operators, too"
diff --git a/elisp/ghc.el b/elisp/ghc.el
index 8224c2f..0d1526b 100644
--- a/elisp/ghc.el
+++ b/elisp/ghc.el
@@ -16,7 +16,7 @@
 
 ;;; Code:
 
-(defconst ghc-version "0.6.1")
+(defconst ghc-version "1.0.0")
 
 ;; (eval-when-compile
 ;;  (require 'haskell-mode))
diff --git a/ghc-mod.cabal b/ghc-mod.cabal
index 0f38f53..cf47f3f 100644
--- a/ghc-mod.cabal
+++ b/ghc-mod.cabal
@@ -1,5 +1,5 @@
 Name:                   ghc-mod
-Version:                0.6.2
+Version:                1.0.0
 Author:                 Kazu Yamamoto <kazu@iij.ad.jp>
 Maintainer:             Kazu Yamamoto <kazu@iij.ad.jp>
 License:                BSD3
@@ -29,8 +29,8 @@ Executable ghc-mod
   else
     GHC-Options:        -Wall
   Build-Depends:        base >= 4.0 && < 5, ghc, ghc-paths, transformers,
-                        process, directory, filepath, old-time,
-                        hlint >= 1.7.1,
+                        process, directory, filepath, old-time, unix,
+                        hlint >= 1.7.1, filemanip,
                         attoparsec, enumerator, attoparsec-enumerator
 Source-Repository head
   Type:                 git