diff --git a/biohazard.cabal b/biohazard.cabal
--- a/biohazard.cabal
+++ b/biohazard.cabal
@@ -1,5 +1,5 @@
 Name:                biohazard
-Version:             0.6.6
+Version:             0.6.6.1
 Synopsis:            bioinformatics support library
 Description:         This is a collection of modules I separated from
                      various bioinformatics tools.  The hope is to make
@@ -29,7 +29,7 @@
 
 Cabal-version:       >=1.9.2
 Build-type:          Custom
--- Tested-With:         GHC == 7.4.2, GHC == 7.6.3, GHC == 7.8.4, GHC == 7.10.3
+Tested-With:         GHC == 7.6.2, GHC == 7.8.4, GHC == 7.10.1
 
 source-repository head
   type:     git
@@ -38,7 +38,7 @@
 source-repository this
   type:     git
   location: https://bitbucket.org/ustenzel/biohazard.git
-  tag:      0.6.6
+  tag:      0.6.6.1
 
 
 Library
diff --git a/src/Bio/Adna.hs b/src/Bio/Adna.hs
--- a/src/Bio/Adna.hs
+++ b/src/Bio/Adna.hs
@@ -23,9 +23,11 @@
 import Bio.Bam
 import Bio.Base
 import Bio.TwoBit
+import Control.Applicative
 import Control.Arrow ( (***) )
 import Control.Monad
 import Data.Bits ( xor )
+import Data.Monoid
 import Data.Vec ( Mat44, Mat44D, identity, getElem, Vec4, (:.)((:.)) )
 
 import qualified Data.Vector.Generic            as G