diff --git a/Data/Set/ExtraG.hs b/Data/Set/ExtraG.hs
--- a/Data/Set/ExtraG.hs
+++ b/Data/Set/ExtraG.hs
@@ -4,7 +4,7 @@
     ) where
 
 import Data.Generics hiding (GT)
-import Control.Monad.Reader
+import Control.Monad (MonadPlus, msum)
 import Data.Set (Set, fromList)
 
 gFind :: forall a b. (Data a, Typeable b, Ord b) => a -> Set b
diff --git a/set-extra.cabal b/set-extra.cabal
--- a/set-extra.cabal
+++ b/set-extra.cabal
@@ -1,5 +1,5 @@
 Name:           set-extra
-Version:        1.4.1
+Version:        1.4.2
 License:        BSD3
 License-File:	COPYING
 Author:         David Fox
@@ -9,9 +9,10 @@
 Maintainer:     David Fox <dsf@seereason.com>
 Homepage:       https://github.com/ddssff/set-extra
 Build-Type:     Simple
-cabal-version:  >= 1.2
+cabal-version:  >= 1.10
 
 Library
-  ghc-options:	-O2 -Wall
+  ghc-options: -Wall
   Exposed-modules: Data.Set.Extra, Data.Set.ExtraG
   Build-Depends: base < 5, containers, mtl, syb
+  Default-Language:   Haskell2010