diff --git a/optparse-generic.cabal b/optparse-generic.cabal
--- a/optparse-generic.cabal
+++ b/optparse-generic.cabal
@@ -1,5 +1,5 @@
 Name: optparse-generic
-Version: 1.2.1
+Version: 1.2.2
 Cabal-Version: >=1.8.0.2
 Build-Type: Simple
 License: BSD3
@@ -27,8 +27,9 @@
         system-filepath      >= 0.3.1   && < 0.5 ,
         text                               < 1.3 ,
         transformers         >= 0.2.0.0 && < 0.6 ,
+        Only                               < 0.2 ,
         optparse-applicative >= 0.12.0  && < 0.15,
-        time                 >= 1.5     && < 1.7 ,
+        time                 >= 1.5     && < 1.9 ,
         void                               < 0.8 ,
         bytestring                         < 0.11,
         semigroups           >= 0.5.0   && < 0.19
diff --git a/src/Options/Generic.hs b/src/Options/Generic.hs
--- a/src/Options/Generic.hs
+++ b/src/Options/Generic.hs
@@ -305,6 +305,7 @@
 import Data.List.NonEmpty (NonEmpty((:|)))
 import Data.Proxy
 import Data.Text (Text)
+import Data.Tuple.Only (Only(..))
 import Data.Typeable (Typeable)
 import Data.Void (Void)
 import Data.Foldable (foldMap)
@@ -585,7 +586,7 @@
 {-| A 1-tuple, used solely to translate `ParseFields` instances into
     `ParseRecord` instances
 -}
-newtype Only a = Only a deriving (Generic, Show)
+newtype Only_ a = Only_ a deriving (Generic, Show)
 
 {-| This is a convenience function that you can use if you want to create a
     `ParseRecord` instance that just defers to the `ParseFields` instance for
@@ -614,7 +615,11 @@
     default parseRecord :: (Generic a, GenericParseRecord (Rep a)) => Parser a
     parseRecord = fmap GHC.Generics.to (genericParseRecord defaultModifiers)
 
-instance ParseFields a => ParseRecord (Only a)
+instance ParseFields a => ParseRecord (Only_ a)
+instance ParseFields a => ParseRecord (Only a) where
+    parseRecord = fmap adapt parseRecord
+      where
+        adapt (Only_ x) = Only x
 
 instance ParseRecord Char where
     parseRecord = fmap getOnly parseRecord