diff --git a/CHANGES.md b/CHANGES.md
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,6 +1,14 @@
 Changes
 =======
 
+Version 1.1
+-----------
+
+* Add a `Serial` instance for `Ratio`
+* Add the `NonEmpty` wrapper for lists
+* Add `listM` (the monadic version of `list`)
+* Add optional explanation for test outcomes
+
 Version 1.0.4
 -------------
 
diff --git a/Test/SmallCheck.hs b/Test/SmallCheck.hs
--- a/Test/SmallCheck.hs
+++ b/Test/SmallCheck.hs
@@ -92,6 +92,7 @@
   -- * Main types and classes
   Testable,
   Property,
+  Reason
 
   ) where
 
diff --git a/Test/SmallCheck/Drivers.hs b/Test/SmallCheck/Drivers.hs
--- a/Test/SmallCheck/Drivers.hs
+++ b/Test/SmallCheck/Drivers.hs
@@ -14,7 +14,7 @@
   smallCheck, smallCheckM, smallCheckWithHook,
   test,
   ppFailure,
-  PropertyFailure(..), PropertySuccess(..), Argument, TestQuality(..)
+  PropertyFailure(..), PropertySuccess(..), Argument, Reason, TestQuality(..)
   ) where
 
 import Control.Monad (when)
diff --git a/Test/SmallCheck/Property.hs b/Test/SmallCheck/Property.hs
--- a/Test/SmallCheck/Property.hs
+++ b/Test/SmallCheck/Property.hs
@@ -9,11 +9,21 @@
 --
 -- Properties and tools to construct them.
 --------------------------------------------------------------------
-{-# LANGUAGE Trustworthy #-}
-  -- Trustworthy is needed because of the hand-written Typeable instance.
-  -- Kind-polymorphic Typeable will solve this.
 {-# LANGUAGE MultiParamTypeClasses, FlexibleInstances, TypeFamilies,
-             ScopedTypeVariables #-}
+             ScopedTypeVariables, DeriveDataTypeable #-}
+
+-- CPP is for Typeable1 vs Typeable
+{-# LANGUAGE CPP #-}
+
+-- Are we using new, polykinded and derivable Typeable yet?
+#define NEWTYPEABLE MIN_VERSION_base(4,7,0)
+
+#if NEWTYPEABLE
+{-# LANGUAGE Safe #-}
+#else
+-- Trustworthy is needed because of the hand-written Typeable instance
+{-# LANGUAGE Trustworthy #-}
+#endif
 module Test.SmallCheck.Property (
   -- * Constructors
   forAll, exists, existsUnique, over, (==>), monadic, changeDepth, changeDepth1,
@@ -21,7 +31,7 @@
   -- * Property's entrails
   Property,
 
-  PropertySuccess(..), PropertyFailure(..), runProperty, TestQuality(..), Argument, Depth, Testable(..),
+  PropertySuccess(..), PropertyFailure(..), runProperty, TestQuality(..), Argument, Reason, Depth, Testable(..),
   ) where
 
 import Test.SmallCheck.Series
@@ -40,6 +50,9 @@
 
 -- | The type of properties over the monad @m@
 newtype Property m = Property { unProperty :: Reader (Env m) (PropertySeries m) }
+#if NEWTYPEABLE
+  deriving Typeable
+#endif
 
 data PropertySeries m =
   PropertySeries
@@ -64,12 +77,16 @@
   | BadTest
   deriving (Eq, Ord, Enum, Show)
 
+#if !NEWTYPEABLE
+-- Typeable here is not polykinded yet, and also GHC doesn't know how to
+-- derive this.
 instance Typeable1 m => Typeable (Property m)
   where
     typeOf _ =
       mkTyConApp
         (mkTyCon3 "smallcheck" "Test.SmallCheck.Property" "Property")
         [typeOf (undefined :: m ())]
+#endif
 
 -- }}}
 
@@ -145,10 +162,25 @@
     let
       success = do
         lift $ testHook env GoodTest
-        if b then return PropertyTrue else mzero
-      failure = PropertyFalse <$ lnot success
+        if b then return $ PropertyTrue Nothing else mzero
+      failure = PropertyFalse Nothing <$ lnot success
     in atomicProperty success failure
 
+-- | Works like the 'Bool' instance, but includes an explanation of the result.
+--
+-- 'Left' and 'Right' correspond to test failure and success
+-- respectively.
+instance Monad m => Testable m (Either Reason Reason) where
+  test r = Property $ reader $ \env ->
+    let
+      success = do
+        lift $ testHook env GoodTest
+        either (const mzero) (pure . PropertyTrue . Just) r
+      failure = do
+        lift $ testHook env GoodTest
+        either (pure . PropertyFalse . Just) (const mzero) r
+    in atomicProperty success failure
+
 instance (Serial m a, Show a, Testable m b) => Testable m (a->b) where
   test = testFunction series
 
@@ -179,7 +211,7 @@
               CounterExample args etc -> CounterExample (arg:args) etc
               _ -> CounterExample [arg] failure
 
-        success = PropertyTrue <$ lnot failure
+        success = PropertyTrue Nothing <$ lnot failure
       -- }}}
 
     Exists -> PropertySeries success failure closest
diff --git a/Test/SmallCheck/Property/Result.hs b/Test/SmallCheck/Property/Result.hs
--- a/Test/SmallCheck/Property/Result.hs
+++ b/Test/SmallCheck/Property/Result.hs
@@ -4,6 +4,7 @@
   ( PropertySuccess(..)
   , PropertyFailure(..)
   , ppFailure
+  , Reason
   , Argument
   ) where
 
@@ -11,10 +12,13 @@
 
 type Argument = String
 
+-- | An explanation for the test outcome
+type Reason = String
+
 data PropertySuccess
   = Exist [Argument] PropertySuccess
   | ExistUnique [Argument] PropertySuccess
-  | PropertyTrue
+  | PropertyTrue (Maybe Reason)
   | Vacuously PropertyFailure
   deriving (Eq, Show)
 
@@ -22,7 +26,7 @@
   = NotExist
   | AtLeastTwo [Argument] PropertySuccess [Argument] PropertySuccess
   | CounterExample [Argument] PropertyFailure
-  | PropertyFalse
+  | PropertyFalse (Maybe Reason)
   deriving (Eq, Show)
 
 class Pretty a where
@@ -43,10 +47,12 @@
     prettyArgs args <+>
     text "such that"
     </> (pretty f)
-  pretty PropertyFalse = text "condition is false"
+  pretty (PropertyFalse Nothing)  = text "condition is false"
+  pretty (PropertyFalse (Just s)) = text s
 
 instance Pretty PropertySuccess where
-  pretty PropertyTrue = text "condition is true"
+  pretty (PropertyTrue Nothing)  = text "condition is true"
+  pretty (PropertyTrue (Just s)) = text s
   pretty (Exist       args s) = existsMsg False args s
   pretty (ExistUnique args s) = existsMsg True args s
   pretty (Vacuously s) = text "property is vacuously true because" </> pretty s
diff --git a/Test/SmallCheck/Series.hs b/Test/SmallCheck/Series.hs
--- a/Test/SmallCheck/Series.hs
+++ b/Test/SmallCheck/Series.hs
@@ -28,6 +28,7 @@
 -- The following is needed for generic instances
 {-# LANGUAGE DefaultSignatures, FlexibleContexts, TypeOperators,
              TypeSynonymInstances, FlexibleInstances, OverlappingInstances #-}
+{-# LANGUAGE Trustworthy #-}
 
 module Test.SmallCheck.Series (
   -- {{{
@@ -148,7 +149,7 @@
   Depth, Series, Serial(..), CoSerial(..),
 
   -- * Convenient wrappers
-  Positive(..), NonNegative(..),
+  Positive(..), NonNegative(..), NonEmpty(..),
 
   -- * Other useful definitions
   (\/), (><), (<~>), (>>-),
@@ -156,7 +157,8 @@
   decDepth,
   getDepth,
   generate,
-  list
+  list,
+  listM
   -- }}}
   ) where
 
@@ -165,6 +167,7 @@
 import Control.Applicative
 import Control.Monad.Identity
 import Data.List
+import Data.Ratio
 import Test.SmallCheck.SeriesMonad
 import GHC.Generics
 
@@ -210,6 +213,10 @@
 list :: Depth -> Series Identity a -> [a]
 list d s = runIdentity $ observeAllT $ runSeries d s
 
+-- | Monadic version of 'list'
+listM :: Monad m => Depth -> Series m a -> m [a]
+listM d s = observeAllT $ runSeries d s
+
 -- | Sum (union) of series
 infixr 7 \/
 (\/) :: Monad m => Series m a -> Series m a -> Series m a
@@ -476,6 +483,15 @@
   coseries rs =
     (. (realToFrac :: Double -> Float)) <$> coseries rs
 
+instance (Integral i, Serial m i) => Serial m (Ratio i) where
+  series = pairToRatio <$> series
+    where
+      pairToRatio (n, Positive d) = n % d
+instance (Integral i, CoSerial m i) => CoSerial m (Ratio i) where
+  coseries rs = (. ratioToPair) <$> coseries rs
+    where
+      ratioToPair r = (numerator r, denominator r)
+
 instance Monad m => Serial m Char where
   series = generate $ \d -> take (d+1) ['a'..'z']
 instance Monad m => CoSerial m Char where
@@ -597,5 +613,14 @@
 
 instance Show a => Show (NonNegative a) where
   showsPrec n (NonNegative x) = showsPrec n x
+
+-- | @NonEmpty xs@: guarantees that @xs@ is not null
+newtype NonEmpty a = NonEmpty { getNonEmpty :: [a] }
+
+instance (Serial m a) => Serial m (NonEmpty a) where
+  series = NonEmpty <$> cons2 (:)
+
+instance Show a => Show (NonEmpty a) where
+  showsPrec n (NonEmpty x) = showsPrec n x
 
 -- }}}
diff --git a/Test/SmallCheck/SeriesMonad.hs b/Test/SmallCheck/SeriesMonad.hs
--- a/Test/SmallCheck/SeriesMonad.hs
+++ b/Test/SmallCheck/SeriesMonad.hs
@@ -6,6 +6,7 @@
 import Control.Monad
 import Control.Monad.Logic
 import Control.Monad.Reader
+import Control.Arrow
 
 -- | Maximum depth of generated test values.
 --
@@ -38,7 +39,11 @@
     , Applicative
     , MonadPlus
     , Alternative
-    , MonadLogic)
+    )
+
+-- This instance is written manually. Using the GND for it is not safe. 
+instance Monad m => MonadLogic (Series m) where
+  msplit (Series a) = Series $ fmap (fmap $ second Series) $ msplit a
 
 instance MonadTrans Series where
   lift a = Series $ lift . lift $ a
diff --git a/smallcheck.cabal b/smallcheck.cabal
--- a/smallcheck.cabal
+++ b/smallcheck.cabal
@@ -1,5 +1,5 @@
 Name:          smallcheck
-Version:       1.0.4
+Version:       1.1
 Cabal-Version: >= 1.6
 License:       BSD3
 License-File:  LICENSE
@@ -27,7 +27,7 @@
 Source-repository this
   type:     git
   location: git://github.com/feuerbach/smallcheck.git
-  tag:      v1.0.4
+  tag:      v1.1
 
 Library