diff --git a/cardano-testnet/cardano-testnet.cabal b/cardano-testnet/cardano-testnet.cabal
index 7d0c209e076..e4473f12d67 100644
--- a/cardano-testnet/cardano-testnet.cabal
+++ b/cardano-testnet/cardano-testnet.cabal
@@ -56,6 +56,8 @@ library
                       , filepath
                       , hedgehog
                       , hedgehog-extras ^>= 0.4.7.0
+                      , microlens
+                      , lens-aeson
                       , mtl
                       , network
                       , network-mux
@@ -76,7 +78,6 @@ library
                       , time
                       , transformers
                       , transformers-except
-                      , unordered-containers
                       , vector
 
   hs-source-dirs:       src
diff --git a/cardano-testnet/src/Testnet/Components/Configuration.hs b/cardano-testnet/src/Testnet/Components/Configuration.hs
index 957e76980e6..812e26c319d 100644
--- a/cardano-testnet/src/Testnet/Components/Configuration.hs
+++ b/cardano-testnet/src/Testnet/Components/Configuration.hs
@@ -24,7 +24,6 @@ import           Control.Monad.IO.Class (MonadIO)
 import           Data.Aeson
 import qualified Data.Aeson as Aeson
 import qualified Data.ByteString.Lazy as LBS
-import qualified Data.HashMap.Lazy as HM
 import qualified Data.List as List
 import           Data.String
 import           Data.Time
@@ -34,11 +33,13 @@ import           System.FilePath.Posix ((</>))
 
 import           Hedgehog
 import qualified Hedgehog as H
-import qualified Hedgehog.Extras.Stock.Aeson as J
 import qualified Hedgehog.Extras.Stock.Time as DTC
 import qualified Hedgehog.Extras.Test.Base as H
 import qualified Hedgehog.Extras.Test.File as H
 
+import qualified Data.Aeson.Lens as L
+import           Lens.Micro
+
 import           Testnet.Defaults
 import           Testnet.Filepath
 import           Testnet.Process.Run (execCli_)
@@ -104,18 +105,12 @@ createSPOGenesisAndFiles testnetOptions startTime (TmpAbsolutePath tempAbsPath')
   -- TODO: Remove this rewrite.
  -- 50 second epochs
  -- Epoch length should be "10 * k / f" where "k = securityParam, f = activeSlotsCoeff"
-  H.rewriteJsonFile createStakedInitialGenesisFile $ J.rewriteObject
-      ( HM.insert "securityParam"          (toJSON @Int 5)    -- TODO: USE config p arameter
-      . HM.adjust
-          (J.rewriteObject
-              $ HM.adjust
-                (J.rewriteObject (HM.insert "major" (toJSON @Int 8)))
-                "protocolVersion"
-          )   "protocolParams"
-      . HM.insert "rho"                    (toJSON @Double 0.1)
-      . HM.insert "tau"                    (toJSON @Double 0.1)
-      . HM.insert "updateQuorum"           (toJSON @Int 2)
-      )
+  H.rewriteJsonFile createStakedInitialGenesisFile $ \o -> o
+    & L.key "securityParam" . L._Integer .~ 5
+    & L.key "rho" . L._Double  .~ 0.1
+    & L.key "tau" . L._Double  .~ 0.1
+    & L.key "updateQuorum" . L._Integer .~ 2
+    & L.key "protocolParams" . L.key "protocolVersion" . L.key "major" . L._Integer .~ 8
 
   execCli_
     [ "genesis", "create-staked"