diff --git a/Main.hs b/Main.hs
--- a/Main.hs
+++ b/Main.hs
@@ -32,9 +32,9 @@
 parseOpts :: O.Parser Options
 parseOpts = Options 
   <$> O.argument O.str (O.metavar "FIELDS")
-  <*> O.strOption (O.metavar "ARRAY-DELIM" <> O.value "," <> O.short 'a' <> O.help "concatentated array elem delimiter. Default to comma")
+  <*> O.strOption (O.metavar "STRING" <> O.value "," <> O.short 'a' <> O.help "concatentated array elem delimiter. Default to comma")
   <*> ((O.flag' CSVOutput (O.short 'c' <> O.long "csv" <> O.help "output CSV"))
-       <|> (TSVOutput <$> (O.strOption (O.metavar "DELIM" <> O.value "\t" <> O.short 'd' <> O.help "output field delimiter. Defaults to tab"))))
+       <|> (TSVOutput <$> (O.strOption (O.metavar "STRING" <> O.value "\t" <> O.short 'd' <> O.help "output field delimiter. Defaults to tab"))))
 
 opts = O.info (O.helper <*> parseOpts)
           (O.fullDesc <> O.progDesc "Transform JSON objects to TSV" <> O.header "jsontsv")
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -80,14 +80,14 @@
 ```
 jsontsv
 
-Usage: jsontsv FIELDS [-a ARRAY-DELIM] ([-c|--csv] | [-d DELIM])
+Usage: jsontsv FIELDS [-a STRING] ([-c|--csv] | [-d STRING])
   Transform JSON objects to TSV
 
 Available options:
   -h,--help                Show this help text
-  -a ARRAY-DELIM           concatentated array element delimiter. Defaults to comma
+  -a STRING                concatentated array elem delimiter. Default to comma
   -c,--csv                 output CSV
-  -d DELIM                 output field delimiter. Defaults to tab
+  -d STRING                output field delimiter. Defaults to tab
 ```
 
 Input should be a stream of JSON objects of the same or mostly similar shape,
diff --git a/jsontsv.cabal b/jsontsv.cabal
--- a/jsontsv.cabal
+++ b/jsontsv.cabal
@@ -2,7 +2,7 @@
 --  see http://haskell.org/cabal/users-guide/
 
 name:                jsontsv
-version:             0.1.3.0
+version:             0.1.3.1
 synopsis:            JSON to TSV transformer
 homepage:            https://github.com/danchoi/jsontsv
 description:         Transforms JSON into tab-separated line-oriented output, for easier processing in Unix-style pipelines.