diff --git a/cardano-api/internal/Cardano/Api/Eras.hs b/cardano-api/internal/Cardano/Api/Eras.hs
index 0fab2d8115..b9b8bfabef 100644
--- a/cardano-api/internal/Cardano/Api/Eras.hs
+++ b/cardano-api/internal/Cardano/Api/Eras.hs
@@ -38,7 +38,7 @@ module Cardano.Api.Eras
 
     -- * Era case handling
 
-  -- ** Case on CardanoEra
+    -- ** Case on CardanoEra
   , caseByronOrShelleyBasedEra
 
     -- ** Case on ShelleyBasedEra
diff --git a/cardano-api/internal/Cardano/Api/Eras/Case.hs b/cardano-api/internal/Cardano/Api/Eras/Case.hs
index 501703002a..784863c2c6 100644
--- a/cardano-api/internal/Cardano/Api/Eras/Case.hs
+++ b/cardano-api/internal/Cardano/Api/Eras/Case.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE EmptyCase #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE LambdaCase #-}
@@ -44,7 +43,10 @@ caseByronOrShelleyBasedEra :: ()
   -> CardanoEra era
   -> a
 caseByronOrShelleyBasedEra l r = \case
-  ByronEra   -> l
+  ByronEra   -> l -- We no longer provide the witness because Byron is isolated.
+                  -- This function will be deleted shortly after build-raw --byron-era is
+                  -- deprecated in cardano-cli
+
   ShelleyEra -> r ShelleyBasedEraShelley
   AllegraEra -> r ShelleyBasedEraAllegra
   MaryEra    -> r ShelleyBasedEraMary
diff --git a/cardano-api/internal/Cardano/Api/InMode.hs b/cardano-api/internal/Cardano/Api/InMode.hs
index a1f690aa99..20a1a922e3 100644
--- a/cardano-api/internal/Cardano/Api/InMode.hs
+++ b/cardano-api/internal/Cardano/Api/InMode.hs
@@ -68,7 +68,7 @@ data TxInMode where
     -> Tx era
     -> TxInMode
 
-  -- | Legacy Byron transactions. Byron has various things we can
+  -- | Legacy Byron transactions and things we can
   -- post to the chain which are not actually transactions.
   -- This covers: update proposals, votes and delegation certs.
   --
@@ -105,8 +105,6 @@ fromConsensusGenTx = \case
     in TxInMode ShelleyBasedEraConway (ShelleyTx ShelleyBasedEraConway shelleyEraTx)
 
 
--- mkByronTx = Consensus.ByronTx (Consensus.byronIdTx tx) tx
-
 toConsensusGenTx :: ()
   => Consensus.CardanoBlock L.StandardCrypto ~ block
   => TxInMode