diff --git a/pipes-key-value-csv.cabal b/pipes-key-value-csv.cabal
--- a/pipes-key-value-csv.cabal
+++ b/pipes-key-value-csv.cabal
@@ -1,5 +1,5 @@
 name:                pipes-key-value-csv
-version:             0.4.0.1
+version:             0.4.0.2
 synopsis:            Streaming processing of CSV files preceded by key-value pairs.
 description:         Nonstandard CSV files, with the table preceded by a header consisting of key-value pairs are often the output format of varius test equipment, such as digital oscilloscopes.
 homepage:            https://github.com/marcinmrotek/key-value-csv
@@ -40,9 +40,9 @@
                      , bifunctors         >= 5.2     && < 5.5
                      , containers         >= 0.5.6   && < 0.6
                      , data-default-class >= 0.0.1   && < 0.2
-                     , lens               >= 4.12    && < 4.15
+                     , lens               >= 4.12    && < 4.16
                      , mtl                >= 2.2     && < 2.3
-                     , pipes              >= 4.1     && < 4.2
+                     , pipes              >= 4.1     && < 4.3
                      , pipes-bytestring   >= 2.1     && < 2.2
                      , pipes-group        >= 1.0     && < 1.1
                      , pipes-parse        >= 3.0     && < 3.1
diff --git a/src/Data/Validation.hs b/src/Data/Validation.hs
--- a/src/Data/Validation.hs
+++ b/src/Data/Validation.hs
@@ -29,20 +29,6 @@
 
 data Validation e a = Success a | Failure e
   deriving (Show, Eq, Ord, Data, Functor, Foldable, Generic)
-  
-toEither :: Validation e a -> Either e a
-toEither (Success a) = Right a
-toEither (Failure e) = Left e
-
-fromEither :: Either e a -> Validation e a
-fromEither (Right a) = Success a
-fromEither (Left e) = Failure e
-
-_Either :: Iso (Validation e1 a1) (Validation e2 a2) (Either e1 a1) (Either e2 a2)
-_Either = iso toEither fromEither
-
-_Validation :: Iso (Either e1 a1) (Either e2 a2) (Validation e1 a1) (Validation e2 a2)
-_Validation = iso fromEither toEither
 
 instance Semigroup e => Semigroup (Validation e a) where
   (<>) = app