diff --git a/Data/StorableVector.hs b/Data/StorableVector.hs
--- a/Data/StorableVector.hs
+++ b/Data/StorableVector.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS_GHC -fglasgow-exts -fno-warn-orphans #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
 --
 -- Module      : StorableVector
 -- Copyright   : (c) The University of Glasgow 2001,
@@ -7,7 +7,7 @@
 --               (c) Don Stewart 2005-2006
 --               (c) Bjorn Bringert 2006
 --               (c) Spencer Janssen 2006
---               (c) Henning Thielemann 2008-2010
+--               (c) Henning Thielemann 2008-2011
 --
 --
 -- License     : BSD-style
diff --git a/Data/StorableVector/Base.hs b/Data/StorableVector/Base.hs
--- a/Data/StorableVector/Base.hs
+++ b/Data/StorableVector/Base.hs
@@ -1,4 +1,7 @@
-{-# OPTIONS_GHC -cpp -fglasgow-exts #-}
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE MagicHash #-}
+{-# LANGUAGE UnboxedTuples #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 --
 -- Module      : Data.StorableVector.Base
 -- License     : BSD-style
diff --git a/Data/StorableVector/Cursor.hs b/Data/StorableVector/Cursor.hs
--- a/Data/StorableVector/Cursor.hs
+++ b/Data/StorableVector/Cursor.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS_GHC -fglasgow-exts #-}
+{-# LANGUAGE ExistentialQuantification #-}
 {- |
 Simulate a list with strict elements by a more efficient array structure.
 -}
@@ -31,15 +31,16 @@
 I hope that this is more efficient.
 With this restriction @s@ cannot be e.g. a function type
 but this would kill performance anyway.
-Functions which need this flexibility may fall back to other data structures
+Functions that need this flexibility may fall back to other data structures
 (lists or chunky StorableVectors) and convert to the Cursor structure later.
 -}
 -- | Cf. StreamFusion  Data.Stream
 data Generator a =
    forall s. -- Seq s =>
       Generator
-         {-# UNPACK #-} !(StateT s Maybe a)  -- compute next value
-         {-# UNPACK #-} !(IORef (Maybe s))   -- current state
+         !(StateT s Maybe a)  -- compute next value
+         {-# UNPACK #-}
+         !(IORef (Maybe s))   -- current state
 
 {- |
 This simulates a
@@ -50,7 +51,7 @@
    Buffer {
        memory :: {-# UNPACK #-} !(ForeignPtr a),
        size   :: {-# UNPACK #-} !Int,  -- size of allocated memory, I think I only need it for debugging
-       gen    :: {-# UNPACK #-} !(Generator a),
+       gen    ::                !(Generator a),  -- we need this indirection for the existential type in Generator
        cursor :: {-# UNPACK #-} !(IORef Int)
    }
 
@@ -156,6 +157,9 @@
 {-# INLINE cons #-}
 {- |
 This is expensive and should not be used to construct lists iteratively!
+A recursion-enabling 'cons' would be 'consN'
+that allocates a buffer of given size,
+initializes the leading cell and sets the buffer pointer to the next cell.
 -}
 cons :: Storable a =>
    a -> Vector a -> Vector a
@@ -221,6 +225,12 @@
                         withForeignPtr p (\q -> pokeElemOff q c a) >>
                         return (Just a)
 
+{-
+It is tempting to turn this into a simple loop without the IORefs.
+This could be compiled to an efficient strict loop,
+but it would fail if the vector content depends on its own,
+like in @fix (consN 1000 'a')@.
+-}
 -- | evaluate all values up to a given position
 evaluateToIO :: Storable a =>
    Int -> Buffer a -> IO ()
diff --git a/Data/StorableVector/Lazy.hs b/Data/StorableVector/Lazy.hs
--- a/Data/StorableVector/Lazy.hs
+++ b/Data/StorableVector/Lazy.hs
@@ -1,5 +1,3 @@
-{-# OPTIONS_GHC -O2 -fglasgow-exts #-}
-{- glasgow-exts are for the rules -}
 {- |
 Chunky signal stream build on StorableVector.
 
diff --git a/storablevector.cabal b/storablevector.cabal
--- a/storablevector.cabal
+++ b/storablevector.cabal
@@ -1,5 +1,5 @@
 Name:                storablevector
-Version:             0.2.7.2
+Version:             0.2.7.3
 Category:            Data
 Synopsis:            Fast, packed, strict storable arrays with a list interface like ByteString
 Description:
@@ -51,13 +51,13 @@
 Source-Repository this
   type:     darcs
   location: http://code.haskell.org/storablevector/
-  tag:      0.2.7.2
+  tag:      0.2.7.3
 
 Library
   Build-Depends:
     non-negative >= 0.1 && <0.2,
     utility-ht >= 0.0.5 && <0.1,
-    transformers >=0.2 && <0.3,
+    transformers >=0.2 && <0.4,
     QuickCheck >= 1 && < 3
 
   If impl(jhc)