diff --git a/Language/Haskell/GhcMod/FileMapping.hs b/Language/Haskell/GhcMod/FileMapping.hs
index 1806017..a3f2f97 100644
--- a/Language/Haskell/GhcMod/FileMapping.hs
+++ b/Language/Haskell/GhcMod/FileMapping.hs
@@ -46,8 +46,10 @@ loadMappedFileSource :: IOish m
                      -> GhcModT m ()
 loadMappedFileSource from src = do
   tmpdir <- cradleTempDir `fmap` cradle
+  enc <- liftIO . mkTextEncoding . optEncoding =<< options
   to <- liftIO $ do
     (fn, h) <- openTempFile tmpdir (takeFileName from)
+    hSetEncoding h enc
     hPutStr h src
     hClose h
     return fn
diff --git a/Language/Haskell/GhcMod/Options/Options.hs b/Language/Haskell/GhcMod/Options/Options.hs
index 82bbda8..72cbe69 100644
--- a/Language/Haskell/GhcMod/Options/Options.hs
+++ b/Language/Haskell/GhcMod/Options/Options.hs
@@ -175,6 +175,11 @@ globalArgSpec = Options
           <=> metavar "OPT"
           <=> help "Option to be passed to GHC"
       <*> many fileMappingSpec
+      <*> strOption
+          $$  long "encoding"
+          <=> value "UTF-8"
+          <=> showDefault
+          <=> help "I/O encoding"
   where
     fileMappingSpec =
       getFileMapping . splitOn '=' <$> strOption
diff --git a/Language/Haskell/GhcMod/Types.hs b/Language/Haskell/GhcMod/Types.hs
index 779c5c9..42dac13 100644
--- a/Language/Haskell/GhcMod/Types.hs
+++ b/Language/Haskell/GhcMod/Types.hs
@@ -105,6 +105,7 @@ data Options = Options {
     -- | GHC command line options set on the @ghc-mod@ command line
   , optGhcUserOptions :: [GHCOption]
   , optFileMappings   :: [(FilePath, Maybe FilePath)]
+  , optEncoding       :: String
   } deriving (Show)
 
 -- | A default 'Options'.
@@ -124,6 +125,7 @@ defaultOptions = Options {
     }
   , optGhcUserOptions = []
   , optFileMappings   = []
+  , optEncoding       = "UTF-8"
   }
 
 ----------------------------------------------------------------
diff --git a/src/GHCMod.hs b/src/GHCMod.hs
index 23e40d4..4a71f61 100644
--- a/src/GHCMod.hs
+++ b/src/GHCMod.hs
@@ -34,9 +34,12 @@ handler = flip gcatches
           ]
 
 main :: IO ()
-main = do
-    hSetEncoding stdout utf8
-    parseArgs >>= \res@(globalOptions, _) ->
+main =
+    parseArgs >>= \res@(globalOptions, _) -> do
+      enc <- mkTextEncoding $ optEncoding globalOptions
+      hSetEncoding stdout enc
+      hSetEncoding stderr enc
+      hSetEncoding stdin enc
       catches (progMain res) [
               Handler $ \(e :: GhcModError) ->
                 runGmOutT globalOptions $ exitError $ renderStyle ghcModStyle (gmeDoc e)
@@ -107,7 +110,6 @@ getFileSourceFromStdin = do
         then fmap (x:) readStdin'
         else return []
 
--- Someone please already rewrite the cmdline parsing code *weep* :'(
 wrapGhcCommands :: (IOish m, GmOut m) => Options -> GhcModCommands -> m ()
 wrapGhcCommands _opts CmdRoot = gmPutStr =<< rootInfo
 wrapGhcCommands opts cmd =
diff --git a/test/FileMappingSpec.hs b/test/FileMappingSpec.hs
index 943465a..d6ba1bb 100644
--- a/test/FileMappingSpec.hs
+++ b/test/FileMappingSpec.hs
@@ -123,13 +123,13 @@ spec = do
             res <- runD $ do
               loadMappedFile "File.hs" "File_Redir_Lint.hs"
               lint defaultLintOpts "File.hs"
-            res `shouldBe` "File.hs:4:1: Error: Eta reduce\NULFound:\NUL  func a b = (*) a b\NULWhy not:\NUL  func = (*)\n"
+            res `shouldBe` "File.hs:4:1: Warning: Eta reduce\NULFound:\NUL  func a b = (*) a b\NULWhy not:\NUL  func = (*)\n"
         it "lints in-memory file if one is specified and outputs original filename" $ do
           withDirectory_ "test/data/file-mapping" $ do
             res <- runD $ do
               loadMappedFileSource "File.hs" "func a b = (++) a b\n"
               lint defaultLintOpts "File.hs"
-            res `shouldBe` "File.hs:1:1: Error: Eta reduce\NULFound:\NUL  func a b = (++) a b\NULWhy not:\NUL  func = (++)\n"
+            res `shouldBe` "File.hs:1:1: Warning: Eta reduce\NULFound:\NUL  func a b = (++) a b\NULWhy not:\NUL  func = (++)\n"
         it "shows types of the expression for redirected files" $ do
             let tdir = "test/data/file-mapping"
             res <- runD' tdir $ do
@@ -184,14 +184,14 @@ spec = do
             res <- runD $ do
               loadMappedFile "File.hs" "File_Redir_Lint.hs"
               lint defaultLintOpts "File.hs"
-            res `shouldBe` "File.hs:6:1: Error: Eta reduce\NULFound:\NUL  func a b = (*) a b\NULWhy not:\NUL  func = (*)\n"
+            res `shouldBe` "File.hs:6:1: Warning: Eta reduce\NULFound:\NUL  func a b = (*) a b\NULWhy not:\NUL  func = (*)\n"
         it "lints in-memory file if one is specified and outputs original filename" $ do
           withDirectory_ "test/data/file-mapping/preprocessor" $ do
             src <- readFile "File_Redir_Lint.hs"
             res <- runD $ do
               loadMappedFileSource "File.hs" src
               lint defaultLintOpts "File.hs"
-            res `shouldBe` "File.hs:6:1: Error: Eta reduce\NULFound:\NUL  func a b = (*) a b\NULWhy not:\NUL  func = (*)\n"
+            res `shouldBe` "File.hs:6:1: Warning: Eta reduce\NULFound:\NUL  func a b = (*) a b\NULWhy not:\NUL  func = (*)\n"
       describe "literate haskell tests" $ do
         it "checks redirected file if one is specified and outputs original filename" $ do
           withDirectory_ "test/data/file-mapping/lhs" $ do
diff --git a/test/LintSpec.hs b/test/LintSpec.hs
index 00876dd..db668ae 100644
--- a/test/LintSpec.hs
+++ b/test/LintSpec.hs
@@ -9,7 +9,7 @@ spec = do
     describe "lint" $ do
         it "can detect a redundant import" $ do
             res <- runD $ lint defaultLintOpts "test/data/hlint/hlint.hs"
-            res `shouldBe` "test/data/hlint/hlint.hs:4:8: Error: Redundant do\NULFound:\NUL  do putStrLn \"Hello, world!\"\NULWhy not:\NUL  putStrLn \"Hello, world!\"\n"
+            res `shouldBe` "test/data/hlint/hlint.hs:4:8: Warning: Redundant do\NULFound:\NUL  do putStrLn \"Hello, world!\"\NULWhy not:\NUL  putStrLn \"Hello, world!\"\n"
 
         context "when no suggestions are given" $ do
             it "doesn't output an empty line" $ do