diff --git a/glob-posix.cabal b/glob-posix.cabal
--- a/glob-posix.cabal
+++ b/glob-posix.cabal
@@ -1,14 +1,14 @@
 name:                glob-posix
-version:             0.1.0.1
+version:             0.2.0.0
 synopsis:            Haskell bindings for POSIX glob library.
 description:         Wrapper for the glob(3) function. The key functions are glob and globMany.
                      GNU extensions are supported but contained in a different module to encourage portability.
 homepage:            https://github.com/rdnetto/glob-posix#readme
 license:             Apache
 license-file:        LICENSE
-author:              Reuben D'Netto
+author:              R D'Netto
 maintainer:          rdnetto@gmail.com
-copyright:           2016 Reuben D'Netto
+copyright:           2016 R D'Netto
 category:            System
 build-type:          Simple
 cabal-version:       >=1.10
@@ -21,7 +21,7 @@
   other-modules:       System.Directory.Glob.Internal
   build-depends:       base >= 4.7 && < 5
   default-language:    Haskell2010
-  ghc-options:         -O2 -Wall
+  ghc-options:         -O2 -Wall -Wextra
 
 test-suite glob-posix-test
   type:                exitcode-stdio-1.0
@@ -36,7 +36,7 @@
                        tasty-hunit,
                        unix
   default-language:    Haskell2010
-  ghc-options:         -O2 -Wall
+  ghc-options:         -O2 -Wall -Wextra
 
 benchmark glob-posix-bench
   type:                exitcode-stdio-1.0
@@ -48,7 +48,7 @@
                        Glob,
                        glob-posix
   default-language:    Haskell2010
-  ghc-options:         -O2 -Wall
+  ghc-options:         -O2 -Wall -Wextra
 
 
 source-repository head
diff --git a/src/System/Directory/Glob/Internal.hsc b/src/System/Directory/Glob/Internal.hsc
--- a/src/System/Directory/Glob/Internal.hsc
+++ b/src/System/Directory/Glob/Internal.hsc
@@ -20,11 +20,15 @@
 data GlobFlag = GlobFlag !CInt
 
 -- | Default value - equivalent to 0 for the C function.
+globDefaults :: GlobFlag
 globDefaults = GlobFlag 0
 
+
+instance Semigroup GlobFlag where
+    (GlobFlag a) <> (GlobFlag b) = GlobFlag (a .|. b)
+
 instance Monoid GlobFlag where
     mempty = globDefaults
-    mappend (GlobFlag a) (GlobFlag b) = GlobFlag (a .|. b)
 
 
 -- | Used for mutation of an existing structure - for internal use only.
diff --git a/test/Spec.hs b/test/Spec.hs
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -10,7 +10,6 @@
 
 import System.Directory.Glob
 import System.Directory.Glob.GNU
-import System.Directory.Glob.GNU.Compat
 
 
 main :: IO ()
@@ -95,17 +94,6 @@
         (createFile f')
         (removeFile f')
         (cb f')
-
--- Creates a temporary directory that we can't read from.
--- Used for testing error handling.
-withUnreadableDir :: (FilePath -> IO a) -> IO a
-withUnreadableDir cb = do
-    fp <- (</> "foo") <$> getTemporaryDirectory
-
-    bracket_
-        (createDirectory fp >> setPermissions fp emptyPermissions)
-        (setPermissions fp emptyPermissions {writable = True} >> removeDirectory fp)
-        (cb fp)
 
 -- Gets the username of the current user
 -- We can't use getLoginName here because it requires a controlling tty