diff --git a/hindent.cabal b/hindent.cabal
--- a/hindent.cabal
+++ b/hindent.cabal
@@ -1,5 +1,5 @@
 name:                hindent
-version:             4.3.3
+version:             4.3.4
 synopsis:            Extensible Haskell pretty printer
 description:         Extensible Haskell pretty printer. Both a library and an executable.
                      .
@@ -40,7 +40,7 @@
   build-depends:     base >= 4 && < 5
                    , hindent
                    , text
-                   , descriptive >= 0.3 && < 0.7
+                   , descriptive >= 0.7 && < 0.8
                    , haskell-src-exts
 
 executable hindent-generate-tests
diff --git a/src/main/Main.hs b/src/main/Main.hs
--- a/src/main/Main.hs
+++ b/src/main/Main.hs
@@ -44,7 +44,8 @@
   deriving (Show)
 
 -- | Program options.
-options :: Consumer [Text] (Option Stoppers) (Style,[Extension])
+options :: Monad m
+        => Consumer [Text] (Option Stoppers) m (Style,[Extension])
 options =
   ver *>
   ((,) <$> style <*> exts)