diff --git a/CHANGES.txt b/CHANGES.txt
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,5 +1,7 @@
 Changelog for CmdArgs
 
+0.10.13
+    #24, support Ratio in some places
 0.10.12
     GHC 7.2 compatibility
 0.10.11
diff --git a/Data/Generics/Any.hs b/Data/Generics/Any.hs
--- a/Data/Generics/Any.hs
+++ b/Data/Generics/Any.hs
@@ -2,12 +2,14 @@
 
 module Data.Generics.Any where
 
+import Control.Exception
 import Control.Monad.Trans.State
 import qualified Data.Data as D
 import Data.Data hiding (toConstr, typeOf, dataTypeOf, isAlgType)
 import Data.List
 import Data.Maybe
 import qualified Data.Typeable.Internal as I
+import System.IO.Unsafe
 
 
 type CtorName = String
@@ -19,6 +21,8 @@
                 | otherwise = Nothing
     where y = init $ tail x
 
+try1 :: a -> Either SomeException a
+try1 = unsafePerformIO . try . evaluate
 
 ---------------------------------------------------------------------
 -- BASIC TYPES
@@ -82,6 +86,7 @@
 
 
 compose0 :: Any -> CtorName -> Any
+compose0 x c | either (const False) (== c) $ try1 $ ctor x = x
 compose0 (Any x) c = Any $ fromConstrB err y `asTypeOf` x
     where Just y = readConstr (D.dataTypeOf x) c
           err = error $ "Data.Generics.Any: Undefined field inside compose0, " ++ c ++ " :: " ++ show (Any x)
diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright Neil Mitchell 2009-2014.
+Copyright Neil Mitchell 2009-2015.
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# CmdArgs: Easy Command Line Processing [![Hackage version](https://img.shields.io/hackage/v/cmdargs.svg?style=flat)](http://hackage.haskell.org/package/cmdargs) [![Build Status](http://img.shields.io/travis/ndmitchell/cmdargs.svg?style=flat)](https://travis-ci.org/ndmitchell/cmdargs)
+# CmdArgs: Easy Command Line Processing [![Hackage version](https://img.shields.io/hackage/v/cmdargs.svg?style=flat)](https://hackage.haskell.org/package/cmdargs) [![Build Status](https://img.shields.io/travis/ndmitchell/cmdargs.svg?style=flat)](https://travis-ci.org/ndmitchell/cmdargs)
 
 <p>
 	CmdArgs is a Haskell library for defining command line parsers. The two features that make it a better choice than the standard <a href="http://haskell.org/ghc/docs/latest/html/libraries/base/System-Console-GetOpt.html">getopt library</a> are:
diff --git a/System/Console/CmdArgs/Explicit/Type.hs b/System/Console/CmdArgs/Explicit/Type.hs
--- a/System/Console/CmdArgs/Explicit/Type.hs
+++ b/System/Console/CmdArgs/Explicit/Type.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 
 module System.Console.CmdArgs.Explicit.Type where
 
@@ -6,7 +7,9 @@
 import Data.Char
 import Data.List
 import Data.Maybe
+#if __GLASGOW_HASKELL__ < 709
 import Data.Monoid
+#endif
 
 
 -- | A name, either the name of a flag (@--/foo/@) or the name of a mode.
diff --git a/System/Console/CmdArgs/Test/Implicit/Tests.hs b/System/Console/CmdArgs/Test/Implicit/Tests.hs
--- a/System/Console/CmdArgs/Test/Implicit/Tests.hs
+++ b/System/Console/CmdArgs/Test/Implicit/Tests.hs
@@ -8,6 +8,7 @@
 import System.Console.CmdArgs.Test.Implicit.Util
 import System.Console.CmdArgs.Quote
 import Data.Int
+import Data.Ratio
 
 
 -- from bug #256 and #231
@@ -392,16 +393,27 @@
     ["--runtime=20"] === Test22 8000 (Just "20")
     fails ["bob"]
 
+-- # 24, doesn't work with Ratio
 
+data Test23 = Test23 {test23A :: Ratio Int} deriving (Show, Data, Typeable, Eq)
+
+mode23 = cmdArgsMode $ Test23 {test23A = 4 % 7 }
+
+test23 = do
+    let Tester{..} = tester "Test23" mode23
+    [] === Test23 (4 % 7)
+    ["--test23=1,6"] === Test23 (1 % 6)
+
+
 -- For some reason, these must be at the end, otherwise the Template Haskell
 -- stage restriction kicks in.
 
 test = test1 >> test2 >> test3 >> test4 >> test5 >> test6 >> test7 >> test8 >> test9 >> test10 >>
        test11 >> test12 >> test13 >> test14 >> test15 >> test16 >> test18 >> test19 >> test20 >>
-       test21 >> test22
+       test21 >> test22 >> test23
 demos = zipWith f [1..]
         [toDemo mode1, toDemo mode2, toDemo mode3, toDemo mode4, toDemo mode5, toDemo mode6
         ,toDemo mode7, toDemo mode8, toDemo mode9, toDemo mode10, toDemo mode11, toDemo mode12
         ,toDemo mode13, toDemo mode14, toDemo mode15, toDemo mode16, toDemo mode17, toDemo mode18
-        ,toDemo mode19, toDemo mode20, toDemo mode21, toDemo mode22]
+        ,toDemo mode19, toDemo mode20, toDemo mode21, toDemo mode22, toDemo mode23]
     where f i x = x{modeHelp = "Testing various corner cases (" ++ show i ++ ")"}
diff --git a/cmdargs.cabal b/cmdargs.cabal
--- a/cmdargs.cabal
+++ b/cmdargs.cabal
@@ -1,13 +1,13 @@
 cabal-version:      >= 1.6
 build-type:         Simple
 name:               cmdargs
-version:            0.10.12
+version:            0.10.13
 license:            BSD3
 license-file:       LICENSE
 category:           Console
 author:             Neil Mitchell <ndmitchell@gmail.com>
 maintainer:         Neil Mitchell <ndmitchell@gmail.com>
-copyright:          Neil Mitchell 2009-2014
+copyright:          Neil Mitchell 2009-2015
 synopsis:           Command line argument processing
 description:
     This library provides an easy way to define command line parsers. Most users
@@ -33,7 +33,7 @@
 extra-source-files:
     README.md
     CHANGES.txt
-tested-with:        GHC==7.8.2, GHC==7.6.3, GHC==7.4.2
+tested-with:        GHC==7.10.1, GHC==7.8.4, GHC==7.6.3, GHC==7.4.2, GHC==7.2.2
 
 source-repository head
     type:     git
@@ -49,7 +49,7 @@
 
 library
     build-depends:
-        base == 4.*,
+        base >= 4.4 && < 5,
         filepath,
         transformers >= 0.2,
         process >= 1.0