diff --git a/.travis.yml b/.travis.yml
index 7a80574..21a22e8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -22,6 +22,9 @@ matrix:
     - env: CABALVER=1.24 GHCVER=8.2.2
       compiler: ": #GHC 8.2.2"
       addons: {apt: {packages: [cabal-install-1.24,ghc-8.2.2], sources: [hvr-ghc]}}
+    - env: CABALVER=1.24 GHCVER=8.4.2
+      compiler: ": #GHC 8.4.2"
+      addons: {apt: {packages: [cabal-install-1.24,ghc-8.4.2], sources: [hvr-ghc]}}
 
 before_install:
  - unset CC
diff --git a/servant-ruby.cabal b/servant-ruby.cabal
index 18b2fcd..a7399e3 100644
--- a/servant-ruby.cabal
+++ b/servant-ruby.cabal
@@ -12,14 +12,13 @@ category:            Servant, Web
 build-type:          Simple
 extra-source-files:  README.md
 cabal-version:       >=1.10
-tested-with:         GHC == 7.10.3, GHC == 8.0.2, GHC == 8.2.2
+tested-with:         GHC == 7.10.3, GHC == 8.0.2, GHC == 8.2.2, GHC == 8.4.2
 
 library
   hs-source-dirs:      src
   exposed-modules:     Servant.Ruby
   build-depends:       base >= 4.8 && < 5
                      , casing >= 0.1 && < 0.2
-                     , lens >= 4.15 && < 4.17
                      , servant-foreign >= 0.9 && < 0.12
                      , text >= 1.2 && < 1.3
   default-language:    Haskell2010
diff --git a/src/Servant/Ruby.hs b/src/Servant/Ruby.hs
index 1621ae8..498e905 100644
--- a/src/Servant/Ruby.hs
+++ b/src/Servant/Ruby.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE RecordWildCards #-}
 
 {-|
@@ -15,9 +16,10 @@ Stability: Experimental
 
 module Servant.Ruby (NameSpace(..), ruby) where
 
-import Control.Lens (filtered, folded, to, view, (^.), (^..), (&))
-
-import Data.Monoid ((<>))
+import Control.Applicative (Const(Const, getConst))
+import Data.Foldable (toList)
+import Data.Function ((&))
+import Data.Monoid (Endo(Endo, appEndo), (<>))
 import Data.Proxy (Proxy(Proxy))
 import Data.Text (Text)
 import Data.Text.Encoding (decodeUtf8')
@@ -231,7 +233,9 @@ public indent req =
     ++ headerArgs
 
   segments :: [Segment NoContent]
-  segments = req ^. reqUrl.path^..folded.filtered isCapture
+  segments = filter isCapture paths
+    where
+    paths = toList (req ^. reqUrl.path)
 
   queryparams :: [QueryArg NoContent]
   queryparams = req ^.. reqUrl.queryStr.traverse
@@ -325,3 +329,27 @@ prop> \str -> snake (snake $ T.pack str) == snake (T.pack str)
 -}
 snake :: Text -> Text
 snake = T.pack . quietSnake . T.unpack
+
+-- optics
+
+to :: (s -> a) -> Getting a s a
+to f a2fa s = s <$ (a2fa $ f s)
+{-# INLINE to #-}
+
+view :: Getting a s a -> s -> a
+view s2a s = getConst (s2a Const s)
+{-# INLINE view #-}
+
+infixl 8 ^.
+
+(^.) :: s -> Getting a s a -> a
+x ^. l = view l x
+{-# INLINE (^.) #-}
+
+infixl 8 ^..
+
+(^..) :: s -> Getting (Endo [a]) s a -> [a]
+x ^.. l = appEndo (getConst $ l (Const . Endo . (:)) x) []
+{-# INLINE (^..) #-}
+
+type Getting r s a = (a -> Const r a) -> s -> Const r s