diff --git a/Distribution/Cab/Commands.hs b/Distribution/Cab/Commands.hs
--- a/Distribution/Cab/Commands.hs
+++ b/Distribution/Cab/Commands.hs
@@ -41,6 +41,7 @@
             | OptStatic
             | OptFuture
             | OptDebug
+            | OptAllowNewer
             deriving (Eq,Show)
 
 ----------------------------------------------------------------
@@ -109,18 +110,23 @@
         mapM_ (hPutStrLn stderr . fullNameOfPkgInfo) (init sortedPkgs)
       else do
         unless doit $ putStrLn "The following packages are deleted without the \"-n\" option."
-        mapM_ (purge doit opts . pairNameOfPkgInfo) sortedPkgs
+        mapM_ (purge doit opts) sortedPkgs
   where
     onlyOne = OptRecursive `notElem` opts
     doit = OptNoharm `notElem` opts
 
-purge :: Bool -> [Option] -> (String,String) -> IO ()
-purge doit opts nameVer = do
+purge :: Bool -> [Option] -> PkgInfo -> IO ()
+purge doit opts pkgInfo = do
     sandboxOpts <- (makeOptList . getSandboxOpts2) <$> getSandbox
     dirs <- getDirs nameVer sandboxOpts
     unregister doit opts nameVer
+    mapM_ unregisterInternal $ findInternalLibs pkgInfo
     mapM_ (removeDir doit) dirs
   where
+    unregisterInternal subname = unregister doit opts (nm,ver)
+      where
+        nm = "z-" ++ name ++ "-z-" ++ subname
+    nameVer@(name,ver) = pairNameOfPkgInfo pkgInfo
     makeOptList "" = []
     makeOptList x  = [x]
 
diff --git a/Distribution/Cab/GenPaths.hs b/Distribution/Cab/GenPaths.hs
--- a/Distribution/Cab/GenPaths.hs
+++ b/Distribution/Cab/GenPaths.hs
@@ -7,7 +7,7 @@
 import Data.List (isSuffixOf)
 import Distribution.Cab.Utils (readGenericPackageDescription, unPackageName)
 import Distribution.Package (pkgName, pkgVersion)
-import Distribution.PackageDescription
+import Distribution.PackageDescription (package, packageDescription)
 import Distribution.Verbosity (silent)
 import Distribution.Version
 import System.Directory
diff --git a/Distribution/Cab/PkgDB.hs b/Distribution/Cab/PkgDB.hs
--- a/Distribution/Cab/PkgDB.hs
+++ b/Distribution/Cab/PkgDB.hs
@@ -19,6 +19,8 @@
   , fullNameOfPkgInfo
   , pairNameOfPkgInfo
   , verOfPkgInfo
+  -- * Find internal libraries
+  , findInternalLibs
   ) where
 
 import Distribution.Cab.Utils
@@ -26,7 +28,7 @@
 import Distribution.Cab.Version
 import Distribution.Cab.VerDB (PkgName)
 import Distribution.InstalledPackageInfo
-    (InstalledPackageInfo, sourcePackageId)
+    (InstalledPackageInfo(depends), sourcePackageId)
 import Distribution.Package (PackageIdentifier(..))
 import Distribution.Simple.Compiler (PackageDB(..))
 import Distribution.Simple.GHC (configure, getInstalledPackages, getPackageDBContents)
@@ -40,7 +42,13 @@
 #endif
 import Distribution.Simple.Program.Db (defaultProgramDb)
 import Distribution.Verbosity (normal)
+import Distribution.Types.UnitId (unUnitId)
 
+import Data.Char
+import Data.Maybe
+
+----------------------------------------------------------------
+
 #if MIN_VERSION_Cabal(1,22,0)
 type PkgDB = InstalledPackageIndex
 #else
@@ -133,3 +141,22 @@
   where
     unitids = map installedUnitId
     topSort = topologicalOrder . fromList . reverseDependencyClosure db
+
+----------------------------------------------------------------
+
+findInternalLibs :: PkgInfo -> [String]
+findInternalLibs pkgInfo =
+    catMaybes $ map (getInternalLib . unUnitId) $ depends pkgInfo
+
+getInternalLib :: String -> Maybe String
+getInternalLib xs0 = case drop 22 $ skip xs0 of
+  _:xs1   -> Just $ take (length xs1) xs1
+  _       -> Nothing
+  where
+    skip ys = case break (== '-') ys of
+      (_,'-':b:bs)
+        | isDigit b -> case break (== '-') bs of
+            (_,'-':ds) -> ds
+            _          -> "" -- error
+        | otherwise -> skip bs
+      _  -> "" -- error
diff --git a/Distribution/Cab/Utils.hs b/Distribution/Cab/Utils.hs
--- a/Distribution/Cab/Utils.hs
+++ b/Distribution/Cab/Utils.hs
@@ -34,7 +34,10 @@
 import qualified Distribution.Package as Cabal (PackageName(..))
 #endif
 
-#if MIN_VERSION_Cabal(2,2,0)
+#if MIN_VERSION_Cabal(3,8,0)
+import qualified Distribution.Simple.PackageDescription as Cabal
+    (readGenericPackageDescription)
+#elif MIN_VERSION_Cabal(2,2,0)
 import qualified Distribution.PackageDescription.Parsec as Cabal
     (readGenericPackageDescription)
 #elif MIN_VERSION_Cabal(2,0,0)
diff --git a/cab.cabal b/cab.cabal
--- a/cab.cabal
+++ b/cab.cabal
@@ -1,5 +1,5 @@
 Name:                   cab
-Version:                0.2.19
+Version:                0.2.20
 Author:                 Kazu Yamamoto <kazu@iij.ad.jp>
 Maintainer:             Kazu Yamamoto <kazu@iij.ad.jp>
 License:                BSD3
diff --git a/src/Commands.hs b/src/Commands.hs
--- a/src/Commands.hs
+++ b/src/Commands.hs
@@ -12,7 +12,7 @@
          command = Sync
        , commandNames = ["sync", "update"]
        , document = "Fetch the latest package index"
-       , routing = RouteCabal ["v1-update"]
+       , routing = RouteCabal ["update"]
        , switches = []
        , manual = Nothing
        }
@@ -31,6 +31,7 @@
                     ,(SwDebug, Solo "--ghc-options=\"-g\"")
                     ,(SwJobs, WithEqArg "--jobs")
                     ,(SwStatic, Solo "--disable-shared")
+                    ,(SwAllowNewer, Solo "--allow-newer")
                     ]
        , manual = Just "[<package> [<ver>]]"
        }
@@ -67,6 +68,7 @@
                     ,(SwExecProfile, Solo "--enable-profiling --ghc-options=\"-fprof-auto -fprof-cafs\"")
                     ,(SwDebug, Solo "--ghc-options=\"-g\"")
                     ,(SwStatic, Solo "--disable-shared")
+                    ,(SwAllowNewer, Solo "--allow-newer")
                     ]
        , manual = Nothing
        }
@@ -108,7 +110,7 @@
          command = Sdist
        , commandNames = ["sdist", "pack"]
        , document = "Make tar.gz for source distribution"
-       , routing = RouteCabal ["v1-sdist"]
+       , routing = RouteCabal ["sdist"]
        , switches = []
        , manual = Nothing
        }
diff --git a/src/Options.hs b/src/Options.hs
--- a/src/Options.hs
+++ b/src/Options.hs
@@ -54,10 +54,13 @@
   , Option ['u'] ["future"]
       (NoArg OptFuture)
       "Show packages with versions ahead of Hackage"
+  , Option ['x'] ["newer"]
+       (NoArg OptAllowNewer)
+      "Allow newer versions"
   , Option ['h'] ["help"]
       (NoArg OptHelp)
       "Show help message"
   ]
 
 optionDB :: OptionDB
-optionDB = zip [SwNoharm,SwRecursive,SwAll,SwInfo,SwFlag,SwTest,SwBench,SwDepsOnly,SwLibProfile,SwExecProfile,SwDebug,SwJobs,SwImport,SwStatic,SwFuture] getOptDB
+optionDB = zip [SwNoharm,SwRecursive,SwAll,SwInfo,SwFlag,SwTest,SwBench,SwDepsOnly,SwLibProfile,SwExecProfile,SwDebug,SwJobs,SwImport,SwStatic,SwFuture,SwAllowNewer] getOptDB
diff --git a/src/Run.hs b/src/Run.hs
--- a/src/Run.hs
+++ b/src/Run.hs
@@ -30,6 +30,7 @@
 toSwitch (OptImport _)  = SwImport
 toSwitch OptStatic      = SwStatic
 toSwitch OptFuture      = SwFuture
+toSwitch OptAllowNewer  = SwAllowNewer
 toSwitch _              = error "toSwitch"
 
 ----------------------------------------------------------------
diff --git a/src/Types.hs b/src/Types.hs
--- a/src/Types.hs
+++ b/src/Types.hs
@@ -24,6 +24,7 @@
             | SwImport
             | SwStatic
             | SwFuture
+            | SwAllowNewer
             deriving (Eq,Show)
 
 ----------------------------------------------------------------