Adapted from: https://github.com/commercialhaskell/stack/commit/4afcf774d2a821e69b6a1afca67bf34341c84e85

--- a/src/Options/Applicative/Complicated.hs
+++ b/src/Options/Applicative/Complicated.hs
@@ -136,20 +136,9 @@ complicatedParser commandMetavar commonP
    (,) <$>
    commonParser <*>
    case runWriter (runExceptT commandParser) of
-     (Right (),d) -> hsubparser' commandMetavar d
+     (Right (), m) -> hsubparser (m <> metavar commandMetavar)
      (Left b,_) -> pure (b,mempty)
 
--- | Subparser with @--help@ argument. Borrowed with slight modification
--- from Options.Applicative.Extra.
-hsubparser' :: String -> Mod CommandFields a -> Parser a
-hsubparser' commandMetavar m = mkParser d g rdr
-  where
-    Mod _ d g = metavar commandMetavar `mappend` m
-    (groupName, cmds, subs) = mkCommand m
-    rdr = CmdReader groupName cmds (fmap add_helper . subs)
-    add_helper pinfo = pinfo
-      { infoParser = infoParser pinfo <**> helpOption }
-
 -- | Non-hidden help option.
 helpOption :: Parser (a -> a)
 helpOption =