diff --git a/midi.cabal b/midi.cabal
--- a/midi.cabal
+++ b/midi.cabal
@@ -1,5 +1,5 @@
 Name:             midi
-Version:          0.2.1.2
+Version:          0.2.1.3
 License:          GPL
 License-File:     LICENSE
 Author:           Henning Thielemann <haskell@henning-thielemann.de>
@@ -30,7 +30,7 @@
 Source-Repository this
   type:     darcs
   location: http://code.haskell.org/~thielema/midi/
-  tag:      0.2.1.2
+  tag:      0.2.1.3
 
 Flag splitBase
   description: Choose the new smaller, split-up base package.
@@ -43,7 +43,7 @@
     explicit-exception >=0.1 && <0.2,
     bytestring >=0.9.0.1 && <0.11,
     binary >=0.4.2 && <0.8,
-    transformers >=0.2 && <0.4,
+    transformers >=0.2 && <0.5,
     monoid-transformer >=0.0.1 && <0.1,
     QuickCheck >=2.1 && <3
   If flag(splitBase)