diff --git a/servant-checked-exceptions.cabal b/servant-checked-exceptions.cabal
--- a/servant-checked-exceptions.cabal
+++ b/servant-checked-exceptions.cabal
@@ -1,5 +1,5 @@
 name:                servant-checked-exceptions
-version:             0.3.0.2
+version:             0.4.0.0
 synopsis:            Checked exceptions for Servant APIs.
 description:         Please see <https://github.com/cdepillabout/servant-checked-exceptions#readme README.md>.
 homepage:            https://github.com/cdepillabout/servant-checked-exceptions
@@ -22,6 +22,7 @@
   exposed-modules:     Servant.Checked.Exceptions
                      , Servant.Checked.Exceptions.Internal
                      , Servant.Checked.Exceptions.Internal.Envelope
+                     , Servant.Checked.Exceptions.Internal.Prism
                      , Servant.Checked.Exceptions.Internal.Product
                      , Servant.Checked.Exceptions.Internal.Servant
                      , Servant.Checked.Exceptions.Internal.Servant.API
@@ -35,7 +36,8 @@
                      , bytestring
                      , deepseq
                      , http-media
-                     , lens
+                     , profunctors
+                     , tagged
                      , servant >= 0.9
                      , servant-client >= 0.9
                      , servant-docs >= 0.9
diff --git a/src/Servant/Checked/Exceptions/Internal/Envelope.hs b/src/Servant/Checked/Exceptions/Internal/Envelope.hs
--- a/src/Servant/Checked/Exceptions/Internal/Envelope.hs
+++ b/src/Servant/Checked/Exceptions/Internal/Envelope.hs
@@ -60,7 +60,6 @@
   ) where
 
 import Control.Applicative ((<|>))
-import Control.Lens (Iso, Prism, Prism', iso, preview, prism)
 import Control.Monad.Fix (MonadFix(mfix))
 import Data.Aeson
        (FromJSON(parseJSON), ToJSON(toJSON), Value, (.=), (.:), object,
@@ -71,6 +70,8 @@
 import Data.Typeable (Typeable)
 import GHC.Generics (Generic)
 
+import Servant.Checked.Exceptions.Internal.Prism
+       (Iso, Prism, Prism', iso, preview, prism)
 import Servant.Checked.Exceptions.Internal.Product (ToOpenProduct)
 import Servant.Checked.Exceptions.Internal.Union
        (IsMember, OpenUnion, catchesOpenUnion, openUnionLift,
@@ -81,12 +82,12 @@
 -- $setup
 -- >>> :set -XDataKinds
 -- >>> :set -XTypeOperators
--- >>> import Control.Lens (preview, review)
 -- >>> import Data.Aeson (encode)
 -- >>> import Data.ByteString.Lazy.Char8 (hPutStrLn)
 -- >>> import Data.Text (Text)
 -- >>> import System.IO (stdout)
 -- >>> import Text.Read (readMaybe)
+-- >>> import Servant.Checked.Exceptions.Internal.Prism (review)
 -- >>> let putByteStrLn = hPutStrLn stdout
 
 
@@ -425,7 +426,7 @@
 -- don't overlap.
 --
 -- For an explanation, see the documentation on the 'FromJSON' instance for
--- 'Union'.
+-- 'Servant.Checked.Exceptions.Internal.Union.Union'.
 instance (FromJSON (OpenUnion es), FromJSON a) => FromJSON (Envelope es a) where
   parseJSON :: Value -> Parser (Envelope es a)
   parseJSON = withObject "Envelope" $ \obj ->
diff --git a/src/Servant/Checked/Exceptions/Internal/Prism.hs b/src/Servant/Checked/Exceptions/Internal/Prism.hs
new file mode 100644
--- /dev/null
+++ b/src/Servant/Checked/Exceptions/Internal/Prism.hs
@@ -0,0 +1,75 @@
+{-# LANGUAGE RankNTypes #-}
+
+{- |
+Module      :  Servant.Checked.Exceptions.Internal.Envelope
+License     :  BSD3
+Maintainer  :  Dennis Gosnell (cdep.illabout@gmail.com)
+Stability   :  experimental
+Portability :  unknown
+
+These functions are for working with Optics popularized by the
+<https://hackage.haskell.org/package/lens lens> package. Documentation can be
+found in the lens package.  These functions are redefined here to remove the
+dependency on the lens package.
+-}
+
+module Servant.Checked.Exceptions.Internal.Prism
+  ( Prism
+  , prism
+  , Prism'
+  , prism'
+  , Iso
+  , iso
+  , review
+  , preview
+  , (<>~)
+  ) where
+
+import Data.Profunctor.Unsafe((#.))
+import Control.Applicative
+import Data.Coerce
+import Data.Functor.Identity
+import Data.Monoid
+import Data.Profunctor
+import Data.Tagged
+
+type Iso s t a b
+   = forall p f. (Profunctor p, Functor f) =>
+                   p a (f b) -> p s (f t)
+
+type Prism s t a b
+   = forall p f. (Choice p, Applicative f) =>
+                   p a (f b) -> p s (f t)
+
+type Prism' s a = Prism s s a a
+
+type ASetter s t a b = (a -> Identity b) -> s -> Identity t
+
+iso :: (s -> a) -> (b -> t) -> Iso s t a b
+iso sa bt = dimap sa (fmap bt)
+{-# INLINE iso #-}
+
+prism :: (b -> t) -> (s -> Either t a) -> Prism s t a b
+prism bt seta = dimap seta (either pure (fmap bt)) . right'
+{-# INLINE prism #-}
+
+prism' :: (a -> s) -> (s -> Maybe a) -> Prism' s a
+prism' bs sma = prism bs (\s -> maybe (Left s) Right (sma s))
+{-# INLINE prism' #-}
+
+review :: Prism' t b -> b -> t
+review p = coerce . p . Tagged . Identity
+{-# INLINE review #-}
+
+preview :: Prism' s a -> s -> Maybe a
+preview l = coerce . l (Const . First . Just)
+{-# INLINE preview #-}
+
+over :: ASetter s t a b -> (a -> b) -> s -> t
+over l f = runIdentity #. l (Identity #. f)
+{-# INLINE over #-}
+
+infixr 4 <>~
+(<>~) :: Monoid a => ASetter s t a a -> a -> s -> t
+l <>~ n = over l (`mappend` n)
+{-# INLINE (<>~) #-}
diff --git a/src/Servant/Checked/Exceptions/Internal/Servant/Docs.hs b/src/Servant/Checked/Exceptions/Internal/Servant/Docs.hs
--- a/src/Servant/Checked/Exceptions/Internal/Servant/Docs.hs
+++ b/src/Servant/Checked/Exceptions/Internal/Servant/Docs.hs
@@ -28,9 +28,9 @@
 
 module Servant.Checked.Exceptions.Internal.Servant.Docs where
 
-import Control.Lens ((&), (<>~))
 import Data.Proxy (Proxy(Proxy))
 import Data.ByteString.Lazy (ByteString)
+import Data.Function ((&))
 import Data.Monoid ((<>))
 import Data.Text (Text)
 import Network.HTTP.Media (MediaType)
@@ -43,6 +43,7 @@
 
 import Servant.Checked.Exceptions.Internal.Envelope
        (Envelope, toErrEnvelope, toSuccEnvelope)
+import Servant.Checked.Exceptions.Internal.Prism ((<>~))
 import Servant.Checked.Exceptions.Internal.Servant.API
        (Throws, Throwing)
 import Servant.Checked.Exceptions.Internal.Util (Snoc)
diff --git a/src/Servant/Checked/Exceptions/Internal/Union.hs b/src/Servant/Checked/Exceptions/Internal/Union.hs
--- a/src/Servant/Checked/Exceptions/Internal/Union.hs
+++ b/src/Servant/Checked/Exceptions/Internal/Union.hs
@@ -67,7 +67,6 @@
 
 -- Imports for Union stuff
 import Control.Applicative ((<|>))
-import Control.Lens (Prism, Prism', iso, preview, prism, prism', review)
 import Control.DeepSeq (NFData(rnf))
 import Data.Aeson
        (FromJSON(parseJSON), ToJSON(toJSON), Value)
@@ -76,6 +75,7 @@
 import Data.Typeable (Typeable)
 import Text.Read (Read(readPrec), ReadPrec, (<++))
 
+import Servant.Checked.Exceptions.Internal.Prism (Prism, Prism', iso, preview, prism, prism', review)
 import Servant.Checked.Exceptions.Internal.Product
        (Product(Cons, Nil), ToOpenProduct, ToProduct, tupleToOpenProduct,
         tupleToProduct)
@@ -492,9 +492,10 @@
 -- >>> p >>= openUnionMatch :: Maybe String
 -- Just "hello"
 --
--- However, imagine are we working with a 'Union' of a 'String' and 'Text'.
--- @\"hello\"@ can be 'read' as both a 'String' and 'Text'.  However, in the
--- following example, it can only be read as a 'String':
+-- However, imagine are we working with a 'Union' of a 'String' and
+-- 'Data.Text.Text'.  @\"hello\"@ can be 'read' as both a 'String' and
+-- 'Data.Text.Text'.  However, in the following example, it can only be read as
+-- a 'String':
 --
 -- >>> let q = readMaybe "Identity \"hello\"" :: Maybe (Union Identity '[String, Text])
 -- >>> q