diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+# 1.0.1
+
+## Added
+- `readField` implementations for the custom `ParseField` instances to
+  accommodate a minor API change in `optparse-generic` version `1.2.3`
+
 # 1.0.0
 
 - Initial release
diff --git a/nix-deploy.cabal b/nix-deploy.cabal
--- a/nix-deploy.cabal
+++ b/nix-deploy.cabal
@@ -1,5 +1,5 @@
 name:                nix-deploy
-version:             1.0.0
+version:             1.0.1
 synopsis:            Deploy Nix-built software to a NixOS machine
 homepage:            https://github.com/awakesecurity/nix-deploy#readme
 license:             Apache-2.0
@@ -35,7 +35,7 @@
               , optparse-applicative >= 0.13.0.0 && < 0.15
               , neat-interpolation                  < 0.4
               , text                 >= 0.7      && < 1.3
-              , turtle               >= 1.3.3    && < 1.4.3
+              , turtle               >= 1.3.6    && < 1.4.3
   default-language:    Haskell2010
 
 source-repository head
diff --git a/src/Main.hs b/src/Main.hs
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -70,6 +70,7 @@
     deriving (Eq, Show, ParseFields)
 
 instance ParseField SwitchMethod where
+  readField = Options.readerError "Internal, fatal error: unexpected use of readField"
   parseField _ _ _ =
         Options.flag' Switch      (Options.long "switch")
     <|> Options.flag' Boot        (Options.long "boot")
@@ -91,6 +92,7 @@
   deriving (Show, ParseFields)
 
 instance ParseField Direction where
+  readField = Options.readerError "Internal, fatal error: unexpected use of readField"
   parseField _ _ _ = (To <$> parseTo) <|> (From <$> parseFrom)
     where
       parseTo    = parser "to" "Deploy software to this address (ex: user@192.168.0.1)"
@@ -113,6 +115,7 @@
 instance ParseFields Line where
 
 instance ParseField Line where
+  readField = Options.maybeReader (textToLine . Text.pack)
   parseField h m c = do
     let metavar = "LINE"
     let line    = Options.maybeReader (textToLine . Text.pack)