diff --git a/TODO.md b/TODO.md
new file mode 100644
--- /dev/null
+++ b/TODO.md
@@ -0,0 +1,33 @@
+TO DO list for LeanCheck
+========================
+
+List of things to do for LeanCheck.
+
+
+documentation
+-------------
+
+* add eg folder with some examples of testing using LeanCheck;
+
+* on tutorial.md, write about how to create test programs;
+
+* on data-invariant.md, write missing section;
+
+* update documentation of `T.LC.Function.*`, mark done/stub/experimental modules;
+
+* review Haddock of all public modules
+
+* find a way to fix links on hackage's README rendering
+  (absolute links to github?)
+
+
+v0.4.1
+------
+
+* rework LeanCheck.Tiers module (simply bagsOf and setsOf);
+
+
+v0.4.2
+------
+
+* implement stub `Test.LeanCheck.Function.*` modules;
diff --git a/leancheck.cabal b/leancheck.cabal
--- a/leancheck.cabal
+++ b/leancheck.cabal
@@ -11,7 +11,7 @@
 -- this cabal file too complicated.  -- Rudy
 
 name:                leancheck
-version:             0.4.0
+version:             0.4.1
 synopsis:            Cholesterol-free property-based testing
 description:
   LeanCheck is a simple enumerative property-based testing library.
@@ -37,9 +37,10 @@
 
 extra-doc-files: README.md
                , CREDITS.md
+               , TODO.md
                , doc/data-invariant.md
                , doc/tutorial.md
-tested-with: GHC==7.10, GHC==7.8, GHC==7.6, GHC==7.4
+tested-with: GHC==8.0, GHC==7.10, GHC==7.8, GHC==7.6, GHC==7.4
 
 
 source-repository head
@@ -49,7 +50,7 @@
 source-repository this
   type:            git
   location:        https://github.com/rudymatela/leancheck
-  tag:             v0.4.0
+  tag:             v0.4.1
 
 library
   exposed-modules: Test.LeanCheck
diff --git a/src/Test/LeanCheck/Derive.hs b/src/Test/LeanCheck/Derive.hs
--- a/src/Test/LeanCheck/Derive.hs
+++ b/src/Test/LeanCheck/Derive.hs
@@ -1,7 +1,8 @@
 {-# LANGUAGE TemplateHaskell, CPP #-}
 -- Experimental module for deriving Listable instances
 --
--- Needs GHC and Template Haskell (tested on GHC 7.4, 7.6, 7.8 and 7.10)
+-- Needs GHC and Template Haskell
+-- (tested on GHC 7.4, 7.6, 7.8, 7.10 and 8.0)
 module Test.LeanCheck.Derive
   ( deriveListable
   )
@@ -126,8 +127,13 @@
 typeArity t = do
   ti <- reify t
   return . length $ case ti of
+#if __GLASGOW_HASKELL__ < 800
     TyConI (DataD    _ _ ks _ _) -> ks
     TyConI (NewtypeD _ _ ks _ _) -> ks
+#else
+    TyConI (DataD    _ _ ks _ _ _) -> ks
+    TyConI (NewtypeD _ _ ks _ _ _) -> ks
+#endif
     _                            -> error $ "error (arity): symbol "
                                          ++ show t
                                          ++ " is not a newtype or data"
@@ -138,8 +144,13 @@
 typeCons t = do
   ti <- reify t
   return . map simplify $ case ti of
+#if __GLASGOW_HASKELL__ < 800
     TyConI (DataD    _ _ _ cs _) -> cs
     TyConI (NewtypeD _ _ _ c  _) -> [c]
+#else
+    TyConI (DataD    _ _ _ _ cs _) -> cs
+    TyConI (NewtypeD _ _ _ _ c  _) -> [c]
+#endif
     _ -> error $ "error (typeConstructors): symbol "
               ++ show t
               ++ " is neither newtype nor data"
@@ -154,5 +165,10 @@
 (|=>|) :: Cxt -> DecsQ -> DecsQ
 c |=>| qds = do ds <- qds
                 return $ map (`ac` c) ds
+#if __GLASGOW_HASKELL__ < 800
   where ac (InstanceD c ts ds) c' = InstanceD (c++c') ts ds
         ac d                   _  = d
+#else
+  where ac (InstanceD o c ts ds) c' = InstanceD o (c++c') ts ds
+        ac d                     _  = d
+#endif