diff --git a/equivalence.cabal b/equivalence.cabal
--- a/equivalence.cabal
+++ b/equivalence.cabal
@@ -1,5 +1,5 @@
 Name:            equivalence
-Version:         0.2.6
+Version:         0.3
 License:         BSD3
 License-File:    LICENSE
 Author:          Patrick Bahr
@@ -31,12 +31,12 @@
   Main-is:		Data_Test.hs
   Other-Modules:	Data.Equivalence.Monad_Test
   hs-source-dirs:	src testsuite/tests
-  Build-Depends:        base >= 4, template-haskell, containers, mtl, QuickCheck >= 2,
+  Build-Depends:        base >= 4, template-haskell, containers, mtl >= 2.2.1, QuickCheck >= 2,
                         test-framework, test-framework-quickcheck2, STMonadTrans
 
 Library
   Build-Depends:
-    base >= 4 && < 5, containers, mtl, STMonadTrans
+    base >= 4 && < 5, containers, mtl >= 2.2.1, STMonadTrans
   Exposed-Modules:
     Data.Equivalence.STT,
     Data.Equivalence.Monad
diff --git a/testsuite/tests/Data/Equivalence/Monad_Test.hs b/testsuite/tests/Data/Equivalence/Monad_Test.hs
--- a/testsuite/tests/Data/Equivalence/Monad_Test.hs
+++ b/testsuite/tests/Data/Equivalence/Monad_Test.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE RankNTypes, TemplateHaskell #-}
 
 module Data.Equivalence.Monad_Test where
@@ -155,7 +156,7 @@
           el = runInt $ do
                  mapM equateAll l1
                  mapM removeClass l2
-                 mapM equateAll l1'
+                 mapM equateAll (l1' :: [[Int]])
                  res <- mapM classDesc l3
                  eq <- equivalent x y
                  return (res,eq)