diff --git a/lib/Database/PostgreSQL/Opium/FromField.hs b/lib/Database/PostgreSQL/Opium/FromField.hs
index 22218e0..5036c8b 100644
--- a/lib/Database/PostgreSQL/Opium/FromField.hs
+++ b/lib/Database/PostgreSQL/Opium/FromField.hs
@@ -148,9 +148,9 @@ instance FromField TimeOfDay where
   validOid Proxy = Oid.time
   parseField = timeToTimeOfDay <$> parseField @DiffTime
 
-newtype RawField = RawField ByteString
+newtype RawField a = RawField a
   deriving (Eq, Show)
 
-instance FromField RawField where
+instance FromField a => FromField (RawField a) where
   validOid Proxy = const True
-  parseField = RawField <$> AP.takeByteString
+  parseField = RawField <$> parseField
diff --git a/test/Database/PostgreSQL/Opium/FromFieldSpec.hs b/test/Database/PostgreSQL/Opium/FromFieldSpec.hs
index 2ec14ff..436ff62 100644
--- a/test/Database/PostgreSQL/Opium/FromFieldSpec.hs
+++ b/test/Database/PostgreSQL/Opium/FromFieldSpec.hs
@@ -94,7 +94,7 @@ newtype ATimeOfDay = ATimeOfDay
 instance FromRow ATimeOfDay where
 
 newtype ARawField = ARawField
-  { raw :: Opium.RawField
+  { raw :: Opium.RawField ByteString
   } deriving (Eq, Generic, Show)
 
 instance FromRow ARawField where