diff --git a/Control/Concurrent/STM/TMVar.hs b/Control/Concurrent/STM/TMVar.hs
--- a/Control/Concurrent/STM/TMVar.hs
+++ b/Control/Concurrent/STM/TMVar.hs
@@ -15,7 +15,7 @@
 
 module Control.Concurrent.STM.TMVar (
 #ifdef __GLASGOW_HASKELL__
-	-- * TVars
+	-- * TMVars
 	TMVar,
 	newTMVar,
 	newEmptyTMVar,
diff --git a/Control/Sequential/STM.hs b/Control/Sequential/STM.hs
--- a/Control/Sequential/STM.hs
+++ b/Control/Sequential/STM.hs
@@ -27,15 +27,28 @@
 	x <- m r
 	unSTM (k x) r
 
+#ifdef BASE4
 atomically :: STM a -> IO a
 atomically (STM m) = do
     r <- newIORef (return ())
+    m r `onException` do
+	rollback <- readIORef r
+	rollback
+#else
+atomically :: STM a -> IO a
+atomically (STM m) = do
+    r <- newIORef (return ())
     m r `catch` \ ex -> do
 	rollback <- readIORef r
 	rollback
 	throw ex
+#endif
 
+#ifdef BASE4
+catchSTM :: Exception e => STM a -> (e -> STM a) -> STM a
+#else
 catchSTM :: STM a -> (Exception -> STM a) -> STM a
+#endif
 catchSTM (STM m) h = STM $ \ r -> do
     old_rollback <- readIORef r
     writeIORef r (return ())
diff --git a/stm.cabal b/stm.cabal
--- a/stm.cabal
+++ b/stm.cabal
@@ -1,19 +1,32 @@
 name:		stm
-version:	2.1.1.0
+version:	2.1.1.2
 license:	BSD3
 license-file:	LICENSE
 maintainer:	libraries@haskell.org
 synopsis:	Software Transactional Memory
+category:       Concurrency
 description:	A modular composable concurrency abstraction.
--- these are the modules exposed by the cut-down non-GHC interface.
-exposed-modules:
-		Control.Concurrent.STM
-		Control.Concurrent.STM.TArray
-		Control.Concurrent.STM.TVar
-		Control.Concurrent.STM.TChan
-		Control.Concurrent.STM.TMVar
-		Control.Monad.STM
-other-modules:
-		Control.Sequential.STM
-build-depends:	base, array
-extensions:	CPP
+build-type:     Simple
+cabal-version:  >=1.2
+
+flag base4
+
+library
+  exposed-modules:
+    Control.Concurrent.STM
+    Control.Concurrent.STM.TArray
+    Control.Concurrent.STM.TVar
+    Control.Concurrent.STM.TChan
+    Control.Concurrent.STM.TMVar
+    Control.Monad.STM
+  other-modules:
+    Control.Sequential.STM
+  build-depends: base < 5, array
+  if flag(base4)
+    build-depends: base >=4
+    cpp-options:   -DBASE4
+  else
+    build-depends: base <4
+  if impl(ghc >= 6.10)
+    build-depends: base >=4
+  extensions:    CPP