diff --git a/Safe/Failure.hs b/Safe/Failure.hs
--- a/Safe/Failure.hs
+++ b/Safe/Failure.hs
@@ -31,6 +31,10 @@
 Safe.Failure.read,
 -- * Useful combinators
 def, note,
+-- * Assertions
+Safe.Failure.assert,
+-- * IO functions
+Safe.Failure.readFile,
 -- * Exceptions
 SafeException(..),
 HeadFailure(..), TailFailure(..), InitFailure(..), LastFailure(..),
@@ -45,9 +49,11 @@
 import Control.Monad.Failure
 import Data.Maybe
 import Data.Typeable
+import Control.Monad.Trans
 #ifdef CME
 import Control.Monad.Exception.Throws
 #endif
+import Control.Monad (liftM)
 
 {-| @def@, use it to return a default value in the event of an error.
 
@@ -198,6 +204,25 @@
 lookup :: (Eq a, MonadFailure (LookupFailure a) m) => a -> [(a,b)] -> m b
 lookup key = maybe (failure (LookupFailure key)) return . Prelude.lookup key
 
+-- | Assert a value to be true. If true, returns the first value as a succss.
+-- Otherwise, returns the second value as a failure.
+assert :: (MonadFailure e m, Exception e)
+       => Bool
+       -> v
+       -> e
+       -> m v
+assert b v e = if b then return v else failure e
+
+-- | The standard readFile function with any 'IOException's returned as a
+-- failure instead of a runtime exception.
+readFile :: (MonadFailure IOException m, MonadIO m) => FilePath -> m String
+readFile fp = do
+    contents <- liftIO $ handle
+                    (\e -> return $ Left (e :: IOException))
+                    (liftM Right $ Prelude.readFile fp)
+    case contents of
+        Left e -> failure e
+        Right v -> return v
 
 #ifdef CME
 
diff --git a/safe-failure.cabal b/safe-failure.cabal
--- a/safe-failure.cabal
+++ b/safe-failure.cabal
@@ -1,7 +1,7 @@
 Name:           safe-failure
 Build-Type:     Simple
 Cabal-Version:  >= 1.2
-Version:        0.1
+Version:        0.2
 License:        BSD3
 License-File:   LICENSE
 Copyright:      2007-8, Neil Mitchell
@@ -9,7 +9,7 @@
 Author:         Neil Mitchell, Jose Iborra (2009), Michael Snoyman (2009)
 Homepage:       http://www-users.cs.york.ac.uk/~ndm/safe/
 Category:       Unclassified
-Synopsis:       Library for safe functions
+Synopsis:       Partial functions from the prelude with a MonadFailure interface
 Description:
     Partial functions from the base library, such as @head@ and @!!@, modified
     to fail in a @MonadFailure@ monad.
@@ -21,20 +21,9 @@
   description: build with special support for control-monad-exception
   default: True
 
-Flag extensibleExceptions
-  description: Use extensible-exception package
-  default: False
-
 Library
    buildable: True
-   build-depends: control-monad-failure
-  if flag(extensibleExceptions)
-    build-depends:
-      extensible-exceptions >= 0.1 && <0.2,
-      base >= 3.0 && <4
-  else
-    build-depends:
-      base >= 4 && < 5
+   build-depends:  base >= 4 && < 5, control-monad-failure, transformers
    exposed-modules:  
       Safe.Failure
    ghc-options: -Wall