diff --git a/CabalDev.hs b/CabalDev.hs
--- a/CabalDev.hs
+++ b/CabalDev.hs
@@ -17,16 +17,22 @@
 modifyOptions :: Options -> IO Options
 modifyOptions opts = found ||> notFound
   where
-    found = addPath opts <$> findCabalDev
+    found = addPath opts <$> findCabalDev (sandbox opts)
     notFound = return opts
 
-findCabalDev :: IO String
-findCabalDev = getCurrentDirectory >>= searchIt . splitPath
+findCabalDev :: Maybe String -> IO FilePath
+findCabalDev (Just path) = do
+    exist <- doesDirectoryExist path
+    if exist then
+        findConf path
+      else
+        findCabalDev Nothing
+findCabalDev Nothing = getCurrentDirectory >>= searchIt . splitPath
 
 addPath :: Options -> String -> Options
 addPath orig_opts path = do
     let orig_ghcopt = ghcOpts orig_opts
-    orig_opts { ghcOpts = orig_ghcopt ++ ["-package-conf", path] }
+    orig_opts { ghcOpts = orig_ghcopt ++ ["-package-conf", path, "-no-user-package-conf"] }
 
 searchIt :: [FilePath] -> IO FilePath
 searchIt [] = throwIO $ userError "Not found"
diff --git a/GHCMod.hs b/GHCMod.hs
--- a/GHCMod.hs
+++ b/GHCMod.hs
@@ -57,6 +57,9 @@
           , Option "o" ["operators"]
             (NoArg (\opts -> opts { operators = True }))
             "print operators, too"
+          , Option "s" ["sandbox"]
+            (ReqArg (\s opts -> opts { sandbox = Just s }) "path")
+            "specify cabal-dev sandbox (default 'cabal-dev`)"
           ]
 
 parseArgs :: [OptDescr (Options -> Options)] -> [String] -> (Options, [String])
diff --git a/Types.hs b/Types.hs
--- a/Types.hs
+++ b/Types.hs
@@ -10,6 +10,7 @@
   , ghcOpts      :: [String]
   , operators    :: Bool
   , expandSplice :: Bool
+  , sandbox      :: Maybe String
   }
 
 defaultOptions :: Options
@@ -19,6 +20,7 @@
   , ghcOpts      = []
   , operators    = False
   , expandSplice = False
+  , sandbox      = Nothing
   }
 
 ----------------------------------------------------------------
diff --git a/elisp/ghc-info.el b/elisp/ghc-info.el
--- a/elisp/ghc-info.el
+++ b/elisp/ghc-info.el
@@ -54,7 +54,7 @@
   (ghc-type-clear-overlay)
   (setq after-change-functions
 	(cons 'ghc-type-clear-overlay after-change-functions))
-  (set (make-local-variable 'post-command-hook) 'ghc-type-post-command-hook))
+  (add-hook 'post-command-hook 'ghc-type-post-command-hook))
 
 (defun ghc-type-clear-overlay (&optional beg end len)
   (when (overlayp ghc-type-overlay)
@@ -63,7 +63,8 @@
     (move-overlay ghc-type-overlay 0 0)))
 
 (defun ghc-type-post-command-hook ()
-  (when (and (overlayp ghc-type-overlay)
+  (when (and (eq major-mode 'haskell-mode)
+	     (overlayp ghc-type-overlay)
 	     (/= (ghc-type-get-point) (point)))
     (ghc-type-clear-overlay)))
 
diff --git a/elisp/ghc.el b/elisp/ghc.el
--- a/elisp/ghc.el
+++ b/elisp/ghc.el
@@ -16,7 +16,7 @@
 
 ;;; Code:
 
-(defconst ghc-version "1.10.11")
+(defconst ghc-version "1.10.13")
 
 ;; (eval-when-compile
 ;;  (require 'haskell-mode))
diff --git a/ghc-mod.cabal b/ghc-mod.cabal
--- a/ghc-mod.cabal
+++ b/ghc-mod.cabal
@@ -1,5 +1,5 @@
 Name:                   ghc-mod
-Version:                1.10.12
+Version:                1.10.13
 Author:                 Kazu Yamamoto <kazu@iij.ad.jp>
 Maintainer:             Kazu Yamamoto <kazu@iij.ad.jp>
 License:                BSD3