diff --git a/cabal.project.local b/cabal.project.local
--- a/cabal.project.local
+++ b/cabal.project.local
@@ -1,3 +1,3 @@
--- constraints: qr-imager +development
+constraints: qr-imager +development
 tests: true
 documentation: true
diff --git a/qr-imager.cabal b/qr-imager.cabal
--- a/qr-imager.cabal
+++ b/qr-imager.cabal
@@ -1,6 +1,6 @@
 cabal-version: 1.18
 name: qr-imager
-version: 2.0.0.0
+version: 2.0.0.1
 license: BSD3
 license-file: LICENSE
 copyright: Copyright: (c) 2016-2018 Vanessa McHale
diff --git a/src/Data/QRCodes.hs b/src/Data/QRCodes.hs
--- a/src/Data/QRCodes.hs
+++ b/src/Data/QRCodes.hs
@@ -27,8 +27,6 @@
 import           Data.QRCodes.Signature
 import           Data.QRCodes.Utils
 import           Data.Word                  (Word8)
-import           Lens.Micro
-import           Lens.Micro.Extras
 import           System.Process
 
 -- | Creates a signed QR code from a strict bytestring and path to keyfile/path.
@@ -64,22 +62,24 @@
 byteStringToQR :: BS.ByteString -> FilePath -> IO ()
 byteStringToQR input filepath = bsToImg input >>= writePng filepath
 
+snd' (_, y, _) = y
+
 -- | given a filepath, read the QR code as a string in all lowercase
 --
 -- > readQRString "picture.jpg"
 readQRString :: FilePath -> IO String
-readQRString filepath = map toLower . init . (drop 8 . view _2) <$> readCreateProcessWithExitCode (shell $ "zbarimg " ++ filepath) ""
+readQRString filepath = map toLower . init . (drop 8 . snd') <$> readCreateProcessWithExitCode (shell $ "zbarimg " ++ filepath) ""
 
 -- | given a filepath pointing to a QR code, get the contents & verify signature with the keyfile
 --
 -- > readQRStrSec "output.png" ".key.hk"
 readQRStrSec :: (Binary a) => FilePath -> FilePath -> IO a
 readQRStrSec filepath keyfile = decode . BSL.pack <$> do
-    enc <- map toLower . init . drop 8 . view _2 <$> readCreateProcessWithExitCode (shell $ "zbarimg " ++ filepath) ""
+    enc <- map toLower . init . drop 8 . snd' <$> readCreateProcessWithExitCode (shell $ "zbarimg " ++ filepath) ""
     fmap (liftEither BS.unpack) . flip checkSigFile keyfile . resolveUpper $ BS.pack enc
 
 -- | Read an image containing a QR code, decode and verify the signature using the given key.
 readQRStrSec' :: (Binary a) => FilePath -> (PublicKey, PrivateKey) -> IO a
 readQRStrSec' filepath key = decode . BSL.pack <$> do
-    enc <- map toLower . init . drop 8 . view _2 <$> readCreateProcessWithExitCode (shell $ "zbarimg " ++ filepath) ""
+    enc <- map toLower . init . drop 8 . snd' <$> readCreateProcessWithExitCode (shell $ "zbarimg " ++ filepath) ""
     fmap (liftEither BS.unpack) . flip checkSig key . resolveUpper $ BS.pack enc
diff --git a/src/Data/QRCodes/Signature.hs b/src/Data/QRCodes/Signature.hs
--- a/src/Data/QRCodes/Signature.hs
+++ b/src/Data/QRCodes/Signature.hs
@@ -8,8 +8,6 @@
 import           Jose.Jwa              (JwsAlg (RS256))
 import           Jose.Jws
 import           Jose.Jwt              (JwtError, unJwt)
-import           Lens.Micro
-import           Lens.Micro.Extras
 import           System.Directory
 
 -- | Verify a signed token with a key
@@ -21,8 +19,8 @@
 -- | Verify a signed token with a key from a given filepath
 checkSig :: BS.ByteString -> (PublicKey, PrivateKey) -> IO (Either JwtError BS.ByteString)
 checkSig tok key = do
-    let jws = rsaDecode (view _1 key) tok
-    return $ fmap (view _2) jws
+    let jws = rsaDecode (fst key) tok
+    pure $ fmap snd jws
 
 -- | Sign a token.
 -- If the key file does not exist, a new key will be generated.
@@ -42,7 +40,7 @@
 -- > mkSig (BS.pack "hello") (generate 256 0x10001)
 mkSig :: BS.ByteString -> (PublicKey, PrivateKey) -> IO BS.ByteString
 mkSig string key = do
-    signedToken <- rsaEncode RS256 (view _2 key) string
+    signedToken <- rsaEncode RS256 (snd key) string
     let signed = fmap unJwt signedToken
     liftEither id (return <$> signed)
 
diff --git a/src/Data/QRCodes/Utils.hs b/src/Data/QRCodes/Utils.hs
--- a/src/Data/QRCodes/Utils.hs
+++ b/src/Data/QRCodes/Utils.hs
@@ -13,7 +13,7 @@
 -- | function applied to byteStrings before saving to QR code so that uppercase/lowercase signatures can be preserverd
 preserveUpper :: BS.ByteString -> BS.ByteString
 preserveUpper = lift pU
-    where pU = concatMap (\c -> if c `elem` ['A'..'Z'] then toLower c : "!" else return c)
+    where pU = (>>= (\c -> if c `elem` ['A'..'Z'] then toLower c : "!" else return c))
 
 -- | resolve coded string to string with uppercase
 resolveUpper :: BS.ByteString -> BS.ByteString