diff --git a/src/Web/Tweet/API.hs b/src/Web/Tweet/API.hs
--- a/src/Web/Tweet/API.hs
+++ b/src/Web/Tweet/API.hs
@@ -3,14 +3,15 @@
 -- | Module containing the functions directly dealing with twitter's API. Most functions in this module have two versions - one which takes a path to a TOML file containing api keys/secrets and tokens/secrets, the other takes api keys/secrets and tokens/secrets as an argument.
 module Web.Tweet.API where
 
+import           Control.Lens
+import           Control.Monad
 import qualified Data.ByteString.Lazy.Char8 as BSL
-import Web.Tweet.Types
-import Web.Tweet.Utils
-import Control.Monad
-import Control.Lens
-import Text.Megaparsec.Error
-import Web.Tweet.Utils.API
-import Data.Composition
+import           Data.Composition
+import           Data.Void
+import           Text.Megaparsec.Error
+import           Web.Tweet.Types
+import           Web.Tweet.Utils
+import           Web.Tweet.Utils.API
 
 -- | Get tweets (text only) for some user
 getMarkov :: String -> Maybe Int -> FilePath -> IO [String]
@@ -21,7 +22,7 @@
 getAll screenName maxId filepath = do
     tweets <- either (error "Parse tweets failed") id <$> getProfileMax screenName 200 filepath maxId
     let lastId = _tweetId . last $ tweets
-    if (Just lastId) == maxId then 
+    if (Just lastId) == maxId then
         pure []
     else
         do
@@ -46,11 +47,11 @@
     pure . (view tweetId) . head . either (error "failed to parse tweet") id . getTweets . BSL.toStrict $ bytes
 
 -- | Gets user profile with max_id set.
-getProfileMax :: String -> Int -> FilePath -> Maybe Int -> IO (Either (ParseError Char Dec) Timeline)
+getProfileMax :: String -> Int -> FilePath -> Maybe Int -> IO (Either (ParseError Char Void) Timeline)
 getProfileMax = fmap (getTweets . BSL.toStrict) .*** getProfileRaw
 
 -- | Gets user profile with max_id set.
-getProfileMaxMem :: String -> Int -> Config -> Maybe Int -> IO (Either (ParseError Char Dec) Timeline)
+getProfileMaxMem :: String -> Int -> Config -> Maybe Int -> IO (Either (ParseError Char Void) Timeline)
 getProfileMaxMem = fmap (getTweets . BSL.toStrict) .*** getProfileRawMem
 
 -- | Gets user profile with max_id set.
@@ -68,11 +69,11 @@
         Nothing -> "?screen_name=" ++ screenName ++ "&count=" ++ (show count) }
 
 -- | Get mentions and parse response as a list of tweets
-mentions :: Int -> FilePath -> IO (Either (ParseError Char Dec) Timeline)
+mentions :: Int -> FilePath -> IO (Either (ParseError Char Void) Timeline)
 mentions = fmap (getTweets . BSL.toStrict) .* mentionsRaw
 
 -- | Get mentions and parse response as a list of tweets
-mentionsMem :: Int -> Config -> IO (Either (ParseError Char Dec) Timeline)
+mentionsMem :: Int -> Config -> IO (Either (ParseError Char Void) Timeline)
 mentionsMem = fmap (getTweets . BSL.toStrict) .* mentionsRawMem
 
 -- | Gets mentions
@@ -86,7 +87,7 @@
     where requestString = "?count=" ++ (show count)
 
 -- | Get user profile given screen name and how many tweets to return
-getProfile :: String -> Int -> FilePath -> IO (Either (ParseError Char Dec) Timeline)
+getProfile :: String -> Int -> FilePath -> IO (Either (ParseError Char Void) Timeline)
 getProfile screenName count filepath = getProfileMax screenName count filepath Nothing
 
 -- | Mute a user given their screen name
@@ -126,11 +127,11 @@
     where requestString = "?count=" ++ (show count)
 
 -- | Get a timeline
-getTimeline :: Int -> FilePath -> IO (Either (ParseError Char Dec) Timeline)
+getTimeline :: Int -> FilePath -> IO (Either (ParseError Char Void) Timeline)
 getTimeline = (fmap (getTweets . BSL.toStrict)) .* getTimelineRaw
 
 -- | Get a timeline
-getTimelineMem :: Int -> Config -> IO (Either (ParseError Char Dec) Timeline)
+getTimelineMem :: Int -> Config -> IO (Either (ParseError Char Void) Timeline)
 getTimelineMem = (fmap (getTweets . BSL.toStrict)) .* getTimelineRawMem
 
 -- | Get a user's timeline and return response as a bytestring
@@ -152,11 +153,11 @@
 deleteTweetMem = (fmap void) . deleteTweetRawMem
 
 -- | Get response, i.e. the tweet deleted
-deleteTweetResponse :: Integer -> FilePath -> IO (Either (ParseError Char Dec) Timeline)
+deleteTweetResponse :: Integer -> FilePath -> IO (Either (ParseError Char Void) Timeline)
 deleteTweetResponse = fmap (getTweets . BSL.toStrict) .* deleteTweetRaw
 
 -- | Get response, i.e. the tweet deleted
-deleteTweetResponseMem :: Integer -> Config -> IO (Either (ParseError Char Dec) Timeline)
+deleteTweetResponseMem :: Integer -> Config -> IO (Either (ParseError Char Void) Timeline)
 deleteTweetResponseMem = fmap (getTweets . BSL.toStrict) .* deleteTweetRawMem
 
 -- | Favorite a tweet given its id
@@ -168,7 +169,7 @@
 favoriteTweetMem = (fmap void) . favoriteTweetRawMem
 
 -- | Favorite a tweet and returned the (parsed) response
-favoriteTweetResponse :: Integer -> FilePath -> IO (Either (ParseError Char Dec) Timeline)
+favoriteTweetResponse :: Integer -> FilePath -> IO (Either (ParseError Char Void) Timeline)
 favoriteTweetResponse = fmap (getTweets . BSL.toStrict) .* favoriteTweetRaw
 
 -- | Unfavorite a tweet given its id
@@ -180,11 +181,11 @@
 unfavoriteTweetMem = (fmap void) . unfavoriteTweetRawMem
 
 -- | Unfavorite a tweet and returned the (parsed) response
-unfavoriteTweetResponse :: Integer -> FilePath -> IO (Either (ParseError Char Dec) Timeline)
+unfavoriteTweetResponse :: Integer -> FilePath -> IO (Either (ParseError Char Void) Timeline)
 unfavoriteTweetResponse = fmap (getTweets . BSL.toStrict) .* unfavoriteTweetRaw
 
 -- | Unfavorite a tweet and returned the (parsed) response
-unfavoriteTweetResponseMem :: Integer -> Config -> IO (Either (ParseError Char Dec) Timeline)
+unfavoriteTweetResponseMem :: Integer -> Config -> IO (Either (ParseError Char Void) Timeline)
 unfavoriteTweetResponseMem = fmap (getTweets . BSL.toStrict) .* unfavoriteTweetRawMem
 
 -- | Unretweet a tweet given its id
@@ -196,11 +197,11 @@
 unretweetTweetMem = (fmap void) . unretweetTweetRawMem
 
 -- | Unretweet a tweet and returned the (parsed) response
-unretweetTweetResponse :: Integer -> FilePath -> IO (Either (ParseError Char Dec) Timeline)
+unretweetTweetResponse :: Integer -> FilePath -> IO (Either (ParseError Char Void) Timeline)
 unretweetTweetResponse = fmap (getTweets . BSL.toStrict) .* unretweetTweetRaw
 
 -- | Unretweet a tweet and returned the (parsed) response
-unretweetTweetResponseMem :: Integer -> Config -> IO (Either (ParseError Char Dec) Timeline)
+unretweetTweetResponseMem :: Integer -> Config -> IO (Either (ParseError Char Void) Timeline)
 unretweetTweetResponseMem = fmap (getTweets . BSL.toStrict) .* unretweetTweetRawMem
 
 -- | Unfollow a user given their screen name
@@ -244,11 +245,11 @@
 retweetTweetMem = (fmap void) . retweetTweetRawMem
 
 -- | Retweet a tweet and returned the (parsed) response
-retweetTweetResponse :: Integer -> FilePath -> IO (Either (ParseError Char Dec) Timeline)
+retweetTweetResponse :: Integer -> FilePath -> IO (Either (ParseError Char Void) Timeline)
 retweetTweetResponse = fmap (getTweets . BSL.toStrict) .* retweetTweetRaw
 
 -- | Retweet a tweet and returned the (parsed) response
-retweetTweetResponseMem :: Integer -> Config -> IO (Either (ParseError Char Dec) Timeline)
+retweetTweetResponseMem :: Integer -> Config -> IO (Either (ParseError Char Void) Timeline)
 retweetTweetResponseMem = fmap (getTweets . BSL.toStrict) .* retweetTweetRawMem
 
 -- | Favorite a tweet given its id; return bytestring response
diff --git a/src/Web/Tweet/API/Internal.hs b/src/Web/Tweet/API/Internal.hs
--- a/src/Web/Tweet/API/Internal.hs
+++ b/src/Web/Tweet/API/Internal.hs
@@ -3,17 +3,18 @@
 -- | Helper functions for the command line tool.
 module Web.Tweet.API.Internal where
 
-import Web.Tweet.API
-import Web.Tweet.Types
-import Web.Tweet.Utils
-import Text.Megaparsec.Error
+import           Data.Void
+import           Text.Megaparsec.Error
+import           Web.Tweet.API
+import           Web.Tweet.Types
+import           Web.Tweet.Utils
 
--- | Show a user profile given screen name, how many tweets to return, 
+-- | Show a user profile given screen name, how many tweets to return,
 -- and whether to print them in color.
 showProfile :: String -> Int -> Bool -> FilePath -> IO String
 showProfile screenName count color = fmap (showTweets color) . getProfile screenName count
 
--- | Show the most successful tweets by a given user, given their screen name. 
+-- | Show the most successful tweets by a given user, given their screen name.
 showBest :: String -> Int -> Bool -> FilePath -> IO String
 showBest screenName n color = fmap (showTweets color . pure . (take n . hits)) . getAll screenName Nothing
 
@@ -23,8 +24,8 @@
 
 -- | Display user timeline
 showTimeline :: Int -> Bool -> FilePath -> IO String
-showTimeline count color = (fmap (showTweets color)) . getTimeline count 
+showTimeline count color = (fmap (showTweets color)) . getTimeline count
 
 -- | Display user timeline in color, as appropriate
-showTweets :: Bool -> Either (ParseError Char Dec) Timeline -> String
+showTweets :: Bool -> Either (ParseError Char Void) Timeline -> String
 showTweets color = (either show id) . (fmap (if color then displayTimelineColor else displayTimeline))
diff --git a/src/Web/Tweet/Exec.hs b/src/Web/Tweet/Exec.hs
--- a/src/Web/Tweet/Exec.hs
+++ b/src/Web/Tweet/Exec.hs
@@ -140,6 +140,8 @@
         <> command "dump" (info dump (progDesc "Dump tweets (for debugging)"))
         <> command "block" (info blockParser (progDesc "Block a user"))
         <> command "unblock" (info unblockParser (progDesc "Unblock a user"))
+        <> command "mute" (info muteParser (progDesc "Mute a user"))
+        <> command "unmute" (info unmuteParser (progDesc "Unmute a user"))
         <> command "mentions" (info mentionsParser (progDesc "Fetch mentions"))))
     <*> (optional $ strOption
         (long "cred"
@@ -184,6 +186,14 @@
 -- | Parser for the unfollow subcommand
 unfol :: Parser Command
 unfol = Unfollow <$> user
+
+-- | Parser for the unfollow subcommand
+muteParser :: Parser Command
+muteParser = Mute <$> user
+
+-- | Parser for the unfollow subcommand
+unmuteParser :: Parser Command
+unmuteParser = Unmute <$> user
 
 -- | Parse a user screen name
 user :: Parser String
diff --git a/src/Web/Tweet/Parser.hs b/src/Web/Tweet/Parser.hs
--- a/src/Web/Tweet/Parser.hs
+++ b/src/Web/Tweet/Parser.hs
@@ -4,9 +4,11 @@
                         , getData ) where
 
 import qualified Data.ByteString as BS
-import Text.Megaparsec.ByteString
-import Text.Megaparsec.Lexer as L
+import qualified Data.ByteString.Char8 as BSW
 import Text.Megaparsec
+import Text.Megaparsec.Byte
+import Text.Megaparsec.Byte.Lexer as L
+import Text.Megaparsec
 import Web.Tweet.Types
 import Data.Monoid
 import qualified Data.Map as M
@@ -14,7 +16,11 @@
 import qualified Data.Text as T
 import qualified Data.Text.Encoding as TE
 import Control.Monad
+import Data.Void
+import Data.Word
 
+type Parser = Parsec Void String
+
 -- | Parse some number of tweets
 parseTweet :: Parser Timeline
 parseTweet = many (try getData <|> (const (TweetEntity "" "" "" 0 Nothing 0 0) <$> eof))
@@ -96,10 +102,10 @@
     string "\\ud"
     str1 <- count 3 anyChar
     str2 <- string "\\ud" >> count 3 anyChar
-    let num = decodeUtf16 $ "d" <> str1 <> "d" <> str2
-    pure . head $ num
+    let num = TE.decodeUtf16BE . BSW.pack $ "d" <> str1 <> "d" <> str2
+    pure . T.head $ num
 
-decodeUtf16 = T.unpack . TE.decodeUtf16BE . BS.concat . go
+decodeUtf16 = TE.decodeUtf16BE . BS.concat . go
     where
         go []             = []
         go (a:b:c:d:rest) = let sym = convert16 [a,b] [c,d] in sym : go rest
@@ -122,11 +128,11 @@
 -- | Parse escaped characters
 specialChar :: Char -> Parser Char
 specialChar c = do
-    string $ "\\" ++ pure c
+    string $ (c:"\\")
     pure c
 
 -- | Convert a string of four hexadecimal digits to an integer.
 fromHex :: BS.ByteString -> Integer
-fromHex = fromRight . (parse (L.hexadecimal :: Parser Integer) "")
-    where fromRight (Right a) = a
-          fromRight (Left x) = error (show x)
+fromHex = fromRight . (parseMaybe (L.hexadecimal :: Parsec Void BS.ByteString Integer))
+    where fromRight (Just a) = a
+          fromRight _        = error "failed to parse hex"
diff --git a/src/Web/Tweet/Utils.hs b/src/Web/Tweet/Utils.hs
--- a/src/Web/Tweet/Utils.hs
+++ b/src/Web/Tweet/Utils.hs
@@ -15,11 +15,12 @@
 import qualified Data.ByteString.Char8       as BS
 import           Data.List
 import           Data.List.Extra
-import           Web.Tweet.Parser.FastParser hiding (text)
+import           Data.Void
+import           Text.Megaparsec
 import           Web.Tweet.Parser
+import           Web.Tweet.Parser.FastParser hiding (text)
 import           Web.Tweet.Types
 import           Web.Tweet.Utils.Colors
-import Text.Megaparsec
 
 -- | filter out retweets, and sort by most successful.
 hits :: Timeline -> Timeline
@@ -41,9 +42,9 @@
 filterQuotes :: Timeline -> Timeline
 filterQuotes = filter ((==Nothing) . (view quoted))
 
--- | Get a list of tweets from a response, returning author, favorites, retweets, and content. 
-getTweets :: BS2.ByteString -> Either (ParseError Char Dec) Timeline
-getTweets = parse parseTweet "" 
+-- | Get a list of tweets from a response, returning author, favorites, retweets, and content.
+getTweets :: BS2.ByteString -> Either (ParseError Char Void) Timeline
+getTweets = parse parseTweet "" . BS.unpack
 
 -- | Get a list of tweets from a response, returning author, favorites, retweets, and content.
 -- This version uses aeson, which it's far faster, but also has worse error messages.
diff --git a/stack.yaml b/stack.yaml
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,39 +1,66 @@
-resolver: lts-8.19
+# This file was automatically generated by 'stack init'
+#
+# Some commonly used options have been documented as comments in this file.
+# For advanced use and comprehensive documentation of the format, please see:
+# https://docs.haskellstack.org/en/stable/yaml_configuration/
+
+# Resolver to choose a 'specific' stackage snapshot or a compiler version.
+# A snapshot resolver dictates the compiler version and the set of packages
+# to be used for project dependencies. For example:
+#
+# resolver: lts-3.5
+# resolver: nightly-2015-09-21
+# resolver: ghc-7.10.2
+# resolver: ghcjs-0.1.0_ghc-7.10.2
+# resolver:
+#  name: custom-snapshot
+#  location: "./custom-snapshot.yaml"
+resolver: lts-9.0
+
+# User packages to be built.
+# Various formats can be used as shown in the example below.
+#
+# packages:
+# - some-directory
+# - https://example.com/foo/bar/baz-0.0.2.tar.gz
+# - location:
+#    git: https://github.com/commercialhaskell/stack.git
+#    commit: e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+# - location: https://github.com/commercialhaskell/stack/commit/e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+#   extra-dep: true
+#  subdirs:
+#  - auto-update
+#  - wai
+#
+# A package marked 'extra-dep: true' will only be built if demanded by a
+# non-dependency (i.e. a user package), and its test suites and benchmarks
+# will not be run. This is useful for tweaking upstream packages.
 packages:
- - .
- - extra-dep: true
-   location:
-       git: https://github.com/haskell/deepseq
-       commit: 0b22c9825ef79c1ee41d2f19e7c997f5cdc93494
- - extra-dep: true
-   location:
-       git: https://github.com/ekmett/semigroupoids.git
-       commit: c3297f970658ae874db098190327ec742044a2e6
- - extra-dep: true
-   location:
-       git: http://github.com/ekmett/lens.git
-       commit: 7031e00f62a704a86c3149c75c1e2afc059af022
- - extra-dep: true
-   location:
-       git: https://github.com/dreixel/syb.git
-       commit: f584ecd525179778063df2eb02dc6bbe406d7e75
-flags:
-    tweet-hs:
-        llvm-fast: true
-        parallel-gc: false
-ghc-options:
-    tweet-hs: -fdiagnostics-color=always
-allow-newer: true
-compiler: ghc-8.2.0.20170507
-compiler-check: match-exact
-setup-info:
- ghc:
-  linux64:
-   8.2.0.20170507:
-    url: https://downloads.haskell.org/~ghc/8.2.1-rc2/ghc-8.2.0.20170507-x86_64-deb8-linux.tar.xz
-  macosx:
-   8.2.0.20170507:
-    url: https://downloads.haskell.org/~ghc/8.2.1-rc2/ghc-8.2.0.20170507-x86_64-apple-darwin.tar.xz
-  windows64:
-   8.2.0.20170507:
-    url: https://downloads.haskell.org/~ghc/8.2.1-rc2/ghc-8.2.0.20170507-x86_64-unknown-mingw32.tar.xz
+- .
+# Dependency packages to be pulled from upstream that are not in the resolver
+# (e.g., acme-missiles-0.3)
+extra-deps: []
+
+# Override default flag values for local packages and extra-deps
+flags: {}
+
+# Extra package databases containing global packages
+extra-package-dbs: []
+
+# Control whether we use the GHC we find on the path
+# system-ghc: true
+#
+# Require a specific version of stack, using version ranges
+# require-stack-version: -any # Default
+# require-stack-version: ">=1.5"
+#
+# Override the architecture used by stack, especially useful on Windows
+# arch: i386
+# arch: x86_64
+#
+# Extra directories used by stack for building
+# extra-include-dirs: [/path/to/dir]
+# extra-lib-dirs: [/path/to/dir]
+#
+# Allow a newer minor version of GHC than the snapshot specifies
+# compiler-check: newer-minor
diff --git a/test/Spec.hs b/test/Spec.hs
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -2,28 +2,19 @@
 
 import qualified Data.ByteString             as BS
 import           Test.Hspec
-import Test.Hspec.Megaparsec
 import           Web.Tweet.Parser.FastParser
-import Web.Tweet.Parser
 import Web.Tweet.Sign
 import Data.Monoid
-import Text.Megaparsec
 import System.Environment
 import Test.QuickCheck
 
 main :: IO ()
 main = hspec $ do
-    describe "aeson parser" $ do
-        file <- runIO $ BS.readFile "test/data"
-        parallel $ it "parses sample tweets wrong" $ do
-            fastParse "" `shouldBe` Left "Error in $: not enough input"
-    describe "handrolled parser" $ do
+    describe "fastParse" $ do
         file <- runIO $ BS.readFile "test/data"
-        parallel $ it "parses sample tweets right" $ do
-            parse parseTweet "test suite" `shouldSucceedOn` file
-    describe "config parser" $ do
         config <- runIO $ (<> "/.cred") <$> getEnv "HOME"
         configToml <- runIO $ (<> "/.cred.toml") <$> getEnv "HOME"
+        parallel $ it "parses sample tweets wrong" $ do
+            fastParse "" `shouldBe` Left "Error in $: not enough input"
         parallel $ it "parses a config file the same way with the toml parser" $
             ((==) <$> mkConfigToml configToml <*> mkConfig config) >>= (`shouldBe` True)
-
diff --git a/tweet-hs.cabal b/tweet-hs.cabal
--- a/tweet-hs.cabal
+++ b/tweet-hs.cabal
@@ -1,5 +1,5 @@
 name:                tweet-hs
-version:             1.0.0.1
+version:             1.0.1.0
 synopsis:            Command-line tool for twitter
 description:         a Command Line Interface Tweeter
 homepage:            https://github.com/vmchale/command-line-tweeter#readme
@@ -53,7 +53,7 @@
                      , http-client
                      , http-types
                      , authenticate-oauth
-                     , megaparsec
+                     , megaparsec >= 6.0
                      , bytestring
                      , split
                      , optparse-applicative 
@@ -120,8 +120,6 @@
                      , hspec
                      , QuickCheck
                      , bytestring
-                     , hspec-megaparsec
-                     , megaparsec
   if flag(gold) 
     ghc-options:       -optl-fuse-ld=gold
     ld-options:        -fuse-ld=gold