diff --git a/diversity.cabal b/diversity.cabal
--- a/diversity.cabal
+++ b/diversity.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                diversity
-version:             0.8.0.1
+version:             0.8.0.2
 synopsis:            Quantify the diversity of a population
 description:         Find the diversity of a collection of entities, mainly for use with fasta sequences.
 homepage:            https://github.com/GregorySchwartz/diversity
@@ -48,3 +48,4 @@
                      , fasta >=0.8
                      , pipes >= 4.1
                      , containers >=0.5
+                     , semigroups
diff --git a/src/src-exec/Main.hs b/src/src-exec/Main.hs
--- a/src/src-exec/Main.hs
+++ b/src/src-exec/Main.hs
@@ -12,10 +12,11 @@
 import qualified System.IO as IO
 
 -- Cabal
-import Options.Applicative
+import Data.Semigroup ((<>))
 import Data.Fasta.String
 import Pipes
 import qualified Pipes.Prelude as P
+import Options.Applicative
 
 -- Local
 import Math.Diversity.Types