diff --git a/Graphics/HGL/Draw/Region.hs b/Graphics/HGL/Draw/Region.hs
--- a/Graphics/HGL/Draw/Region.hs
+++ b/Graphics/HGL/Draw/Region.hs
@@ -143,8 +143,9 @@
   return (MkRegion r)
 
 regionToGraphic (MkRegion r) = mkDraw $ \ dc -> do
+  (_, _, _, width, height, _, _) <- X.getGeometry (disp dc) (drawable dc)
   X.setRegion (disp dc) (brushGC dc) r
-  X.fillRectangle (disp dc) (drawable dc) (brushGC dc) 0 0 (-1) (-1)  -- entire window (in 2s complement!)
+  X.fillRectangle (disp dc) (drawable dc) (brushGC dc) 0 0 width height
   X.setRegion (disp dc) (brushGC dc) emptyXRegion
   return ()
 
diff --git a/Graphics/HGL/Internals/Events.hs b/Graphics/HGL/Internals/Events.hs
--- a/Graphics/HGL/Internals/Events.hs
+++ b/Graphics/HGL/Internals/Events.hs
@@ -18,9 +18,11 @@
         getTick, sendTick
 	) where
 
+import Control.Concurrent.STM (atomically)
+import Control.Concurrent.STM.TChan(TChan, newTChanIO, readTChan, writeTChan, isEmptyTChan)
+
 import Graphics.HGL.Internals.Event
 import Graphics.HGL.Internals.Flag
-import Control.Concurrent.Chan(Chan, newChan, readChan, writeChan, isEmptyChan)
 
 ----------------------------------------------------------------
 -- Interface
@@ -37,6 +39,8 @@
 -- of the Graphics library).  Exposure events in X11 behave in a
 -- similar way except that they do not overtake other events.)
 
+type Chan = TChan
+
 data Events = Events { events :: Chan Event
                      , tick   :: Flag ()
                      }
@@ -62,6 +66,25 @@
 sendEvent evs = writeChan   (events evs)
 sendTick  evs = setFlag     (tick evs) ()
 getTick   evs = resetFlag   (tick evs)
+
+----------------------------------------------------------------
+-- TChan wrappers
+--
+-- As `isEmptyChan` was removed by
+-- http://hackage.haskell.org/trac/ghc/ticket/4154, we can follow
+-- suggestions in there and just replace Chan with TChan.
+----------------------------------------------------------------
+newChan :: IO (Chan a)
+newChan = newTChanIO
+
+readChan :: Chan a -> IO a
+readChan = atomically . readTChan
+
+writeChan :: Chan a -> a -> IO ()
+writeChan c v = atomically $ writeTChan c v
+
+isEmptyChan :: Chan a -> IO Bool
+isEmptyChan = atomically . isEmptyTChan
 
 ----------------------------------------------------------------
 -- End
diff --git a/HGL.cabal b/HGL.cabal
--- a/HGL.cabal
+++ b/HGL.cabal
@@ -1,5 +1,5 @@
 name:		HGL
-version:	3.2.3.1
+version:	3.2.3.2
 license:	BSD3
 license-file:	LICENSE
 author: 	Alastair Reid
@@ -7,14 +7,14 @@
 category:	Graphics
 synopsis:	A simple graphics library based on X11 or Win32
 description:
-	A simple graphics library, designed to give the programmer access
-	to most interesting parts of the Win32 Graphics Device Interface
-	and X11 library without exposing the programmer to the pain and
-	anguish usually associated with using these interfaces.
-	.
-	The library also includes a module Graphics.SOE providing the
-	interface used in "The Haskell School of Expression", by Paul
-	Hudak, cf <http://www.haskell.org/soe/>.
+        A simple graphics library, designed to give the programmer access
+        to most interesting parts of the Win32 Graphics Device Interface
+        and X11 library without exposing the programmer to the pain and
+        anguish usually associated with using these interfaces.
+        .
+        The library also includes a module Graphics.SOE providing the
+        interface used in "The Haskell School of Expression", by Paul
+        Hudak, cf <http://www.haskell.org/soe/>.
 build-type:	Simple
 cabal-version:	>= 1.2.1
 
@@ -22,7 +22,7 @@
 
 library
   if flag(split-base)
-    build-depends: base >= 4.4.0.0 && < 5, array
+    build-depends: base >= 4.4.0.0 && < 5, array, stm
   else
     build-depends: base < 2
   exposed-modules: