diff --git a/alea.cabal b/alea.cabal
--- a/alea.cabal
+++ b/alea.cabal
@@ -1,5 +1,5 @@
 name:                alea
-version:             0.5.1.0
+version:             0.5.2.0
 synopsis:            a diceware passphrase generator
 description:
 
diff --git a/src/Main.hs b/src/Main.hs
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -4,6 +4,7 @@
 
 import Control.Monad             (when, forever)
 import Data.Text                 (unpack)
+import Data.Monoid
 import Options.Applicative
 import Alea.Diceware
 import Paths_alea                (getDataFileName)