diff --git a/Control/Concurrent/AdvSTM.hs b/Control/Concurrent/AdvSTM.hs
--- a/Control/Concurrent/AdvSTM.hs
+++ b/Control/Concurrent/AdvSTM.hs
@@ -46,7 +46,7 @@
     MonadAdvSTM(..), handleSTM, TVar( TVar ), onCommitLock, currentTid, valueTVar )
 -- import Control.Monad.Reader(ReaderT(ReaderT),mapReaderT,runReaderT)
 
-import Control.Exception(Exception,throw,catch,SomeException,fromException,try,block,Deadlock(..),finally) 
+import Control.Exception(Exception,throw,catch,SomeException,fromException,try,mask_,Deadlock(..),finally) 
 import Control.Monad(mplus,when,liftM,ap,unless)
 import Control.Monad.Error(MonadError(..))
 import Control.Concurrent(threadDelay,forkIO,ThreadId,myThreadId,throwTo)
@@ -205,7 +205,7 @@
     let wrappedAction = runReaderT action env -- `S.orElse` check'retry
 
     -- Block exceptions from other threads for the rest of 'atomically'
-    block $ do 
+    mask_ $ do 
         result <- S.atomically $ do 
             debugSTM (show (tid,"wrappedAction: Running S.STM action...")) 0 debugging
             result <- wrappedAction
diff --git a/stm-io-hooks.cabal b/stm-io-hooks.cabal
--- a/stm-io-hooks.cabal
+++ b/stm-io-hooks.cabal
@@ -24,7 +24,7 @@
 Maintainer:     Peter Robinson <thaldyron@gmail.com>
 License:        BSD3
 License-file:   LICENSE
-Version:        1.0.0
+Version:        1.0.1
 
 Build-type:     Simple                        
 Cabal-Version:  >= 1.6
@@ -45,10 +45,10 @@
                    Control.Monad.AdvSTM.Class
                    
     build-depends:  base       >= 4 && < 5
-                   ,stm        >= 2.1.1.2 && < 2.5
-                   ,array      >= 0.2.0.0 && < 0.5
-                   ,containers >= 0.2.0.0 && < 0.6
-                   ,mtl        >= 1.1.0.2 && < 2.2
+                   ,stm        >= 2.1.1.2 
+                   ,array      >= 0.2.0.0 
+                   ,containers >= 0.2.0.0 
+                   ,mtl        >= 1.1.0.2 
 
     extensions:    MultiParamTypeClasses
                    FunctionalDependencies