diff --git a/CHANGES.txt b/CHANGES.txt
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,3 +1,15 @@
+0.3.5
+-----
+* compatibility with GHC 8.8
+
+0.3.4
+-----
+* MonadFail instance for EquivT
+
+0.3.3
+-----
+* compatibility with GHC 8.6
+
 0.3.2
 -----
 * add Applicative constraints for backwards compatibility with GHC 7.8
diff --git a/equivalence.cabal b/equivalence.cabal
--- a/equivalence.cabal
+++ b/equivalence.cabal
@@ -1,5 +1,5 @@
 Name:            equivalence
-Version:         0.3.4
+Version:         0.3.5
 License:         BSD3
 License-File:    LICENSE
 Author:          Patrick Bahr
@@ -34,8 +34,7 @@
   Other-Modules:	Data.Equivalence.Monad_Test,Data.Equivalence.Monad, Data.Equivalence.STT
   hs-source-dirs:	src testsuite/tests
   Build-Depends:        base >= 4, template-haskell, containers, mtl >= 2.0.1, QuickCheck >= 2,
-                        test-framework, test-framework-quickcheck2, STMonadTrans >= 0.4.3,
-                        transformers >= 0.2, transformers-compat >= 0.3, fail
+                        STMonadTrans >= 0.4.3, transformers >= 0.2, transformers-compat >= 0.3, fail
 
 Library
   Build-Depends:
diff --git a/src/Data/Equivalence/Monad.hs b/src/Data/Equivalence/Monad.hs
--- a/src/Data/Equivalence/Monad.hs
+++ b/src/Data/Equivalence/Monad.hs
@@ -55,7 +55,6 @@
 import Control.Monad.Trans.Error (ErrorT)
 import Control.Monad.Trans.Except (ExceptT)
 import Control.Applicative
-
 import qualified Control.Monad.Fail as Fail
 
 
diff --git a/src/Data/Equivalence/STT.hs b/src/Data/Equivalence/STT.hs
--- a/src/Data/Equivalence/STT.hs
+++ b/src/Data/Equivalence/STT.hs
@@ -241,9 +241,9 @@
 
 
 
-{-| This function equates the two given elements. That is, it unions
-the equivalence classes of the two elements and combines their
-descriptor. The returned entry is the representative of the new
+{-| This function equates the two given (representative) elements. That
+is, it unions the equivalence classes of the two elements and combines
+their descriptor. The returned entry is the representative of the new
 equivalence class -}
 
 equateEntry :: (Monad m, Applicative m, Ord a) => Equiv s c a -> Entry s c a -> Entry s c a -> STT s m (Entry s c a)
@@ -264,7 +264,9 @@
           writeSTRef ry dy{entryWeight = wx + wy, entryDesc = mkDesc chx chy}
           return repy
 
-      _ -> fail "error on `equateEntry`"
+      _ -> error "error on `equateEntry`"
+      -- this should not happen as this function is only called by
+      -- 'combineEntries', which always uses representative entries
   else return  repx
 
 combineEntries :: (Monad m, Applicative m, Ord a)
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
@@ -3,8 +3,6 @@
 
 module Data.Equivalence.Monad_Test where
 
-import Test.Framework
-import Test.Framework.Providers.QuickCheck2
 import Test.QuickCheck hiding ((===))
 
 import Data.Equivalence.Monad
@@ -13,29 +11,13 @@
 import Data.Set (Set)
 import qualified Data.Set as Set
 
+
+
 --------------------------------------------------------------------------------
 -- Test Suits
 --------------------------------------------------------------------------------
 
-main = defaultMain [tests]
 
-tests = testGroup "Monad" [testProperty "singleton" prop_singleton,
-         testProperty "equateAll" prop_equateAll,
-         testProperty "combineAll" prop_combineAll,
-         testProperty "equate" prop_equate,
-         testProperty "combine" prop_combine,
-         testProperty "equateOverlap" prop_equateOverlap,
-         testProperty "combineOverlap" prop_combineOverlap,
-         testProperty "equateAllOverlap" prop_equateAllOverlap,
-         testProperty "combineAllOverlap" prop_combineAllOverlap,
-         testProperty "removeClass" prop_removeClass,
-         testProperty "remove" prop_remove,
-         testProperty "removeClass'" prop_removeClass',
-         testProperty "remove'" prop_remove',
-         testProperty "classes" prop_classes
-         ]
-
-
 -- run :: (Ord a) => STT s Identity (Equiv s (Set a) a)
 run :: (Ord v) => (forall s. EquivM s (Set v) v a) -> a
 run = runEquivM Set.singleton Set.union
@@ -172,3 +154,8 @@
                  [cx,cy] <- getClasses [x,y]
                  eq <- cx === cy
                  return (res,eq)
+
+
+return []
+main = $quickCheckAll
+
diff --git a/testsuite/tests/Data_Test.hs b/testsuite/tests/Data_Test.hs
--- a/testsuite/tests/Data_Test.hs
+++ b/testsuite/tests/Data_Test.hs
@@ -1,17 +1,12 @@
 module Main where
 
-import Test.Framework
 import qualified Data.Equivalence.Monad_Test
 
 --------------------------------------------------------------------------------
 -- Test Suits
 --------------------------------------------------------------------------------
 
-main = defaultMain [tests]
-
-tests = testGroup "Data" [
-         Data.Equivalence.Monad_Test.tests
-       ]
+main = Data.Equivalence.Monad_Test.main
 
 --------------------------------------------------------------------------------
 -- Properties