diff --git a/HTk/Kernel/GUIObject.hs b/HTk/Kernel/GUIObject.hs
--- a/HTk/Kernel/GUIObject.hs
+++ b/HTk/Kernel/GUIObject.hs
@@ -1,7 +1,3 @@
-{-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE UndecidableInstances #-}
-{-# LANGUAGE OverlappingInstances #-}
-
 module HTk.Kernel.GUIObject(
 
   GUIObject(..),
@@ -44,9 +40,6 @@
   cget            :: GUIValue a => w -> ConfigID -> IO a
   cset w cid v    = setConfig (toGUIObject w) cid v >> return w
   cget w cid      = getConfig (toGUIObject w) cid
-
-instance GUIObject w => Eq w where
-  w1 == w2 = toGUIObject w1 == toGUIObject w2
 
 setConfig :: GUIValue a => GUIOBJECT -> ConfigID -> a -> IO ()
 setConfig (GUIOBJECT _ ostref) cid val =
diff --git a/uni-htk.cabal b/uni-htk.cabal
--- a/uni-htk.cabal
+++ b/uni-htk.cabal
@@ -1,5 +1,5 @@
 name:           uni-htk
-version:        2.2.1.0
+version:        2.2.1.1
 build-type:     Simple
 license:        LGPL
 license-file:   LICENSE
@@ -10,7 +10,7 @@
 synopsis:       Graphical User Interface for Haskell Programs
 description:    GUI toolkit based on Tcl\/Tk
 cabal-version:  >= 1.4
-Tested-With:    GHC==6.10.4, GHC==6.12.3
+Tested-With:    GHC==6.10.4, GHC==6.12.3, GHC==7.0.4
 
 flag debug
   description: add debug traces