diff --git a/cabal.project b/cabal.project
index 1e62c863fce..31a62773098 100644
--- a/cabal.project
+++ b/cabal.project
@@ -104,8 +104,8 @@ source-repository-package
   type: git
   location: https://github.com/tweag/cardano-cls.git
   subdir: merkle-tree-incremental mempack-scls scls-cbor scls-cardano scls-format scls-core
-  --sha256: sha256-BoAotLgxMipOIMcZrmlr6EtQzqC5HyEA0ZpK8nvCmJs=
-  tag: 5161deb34247a51160f2e8d58b6cc2d48044ea2c
+  --sha256: sha256-02j6m1UBYiZrdgAzGFb5yO+tFf8pN6DmykZjk9tdOUg=
+  tag: 940f6ad992382e856082f73c437a162211e50ba8
 
 constraints:
   -- Happy version 2.2.1 fails to compile haskell-src-exts
diff --git a/libs/cardano-ledger-canonical-state/cardano-ledger-canonical-state.cabal b/libs/cardano-ledger-canonical-state/cardano-ledger-canonical-state.cabal
index b5acbe4ae2b..1ff6dc3db01 100644
--- a/libs/cardano-ledger-canonical-state/cardano-ledger-canonical-state.cabal
+++ b/libs/cardano-ledger-canonical-state/cardano-ledger-canonical-state.cabal
@@ -45,6 +45,7 @@ library
     Cardano.Ledger.CanonicalState.Namespace
     Cardano.Ledger.CanonicalState.Namespace.Blocks.V0
     Cardano.Ledger.CanonicalState.Namespace.EntitiesCommittee.V0
+    Cardano.Ledger.CanonicalState.Namespace.EntitiesDormantEpochs.V0
     Cardano.Ledger.CanonicalState.Namespace.GovCommittee.V0
     Cardano.Ledger.CanonicalState.Namespace.GovConstitution.V0
     Cardano.Ledger.CanonicalState.Namespace.GovPParams.V0
diff --git a/libs/cardano-ledger-canonical-state/conway/Cardano/Ledger/CanonicalState/Conway.hs b/libs/cardano-ledger-canonical-state/conway/Cardano/Ledger/CanonicalState/Conway.hs
index 171c3a013d3..1822c8e7525 100644
--- a/libs/cardano-ledger-canonical-state/conway/Cardano/Ledger/CanonicalState/Conway.hs
+++ b/libs/cardano-ledger-canonical-state/conway/Cardano/Ledger/CanonicalState/Conway.hs
@@ -64,6 +64,8 @@ type instance NamespaceEra "blocks/v0" = ConwayEra
 
 type instance NamespaceEra "entities/committee/v0" = ConwayEra
 
+type instance NamespaceEra "entities/dormant_epochs/v0" = ConwayEra
+
 type instance NamespaceEra "gov/committee/v0" = ConwayEra
 
 type instance NamespaceEra "gov/constitution/v0" = ConwayEra
diff --git a/libs/cardano-ledger-canonical-state/src/Cardano/Ledger/CanonicalState/Namespace/EntitiesDormantEpochs/V0.hs b/libs/cardano-ledger-canonical-state/src/Cardano/Ledger/CanonicalState/Namespace/EntitiesDormantEpochs/V0.hs
new file mode 100644
index 00000000000..557757996d0
--- /dev/null
+++ b/libs/cardano-ledger-canonical-state/src/Cardano/Ledger/CanonicalState/Namespace/EntitiesDormantEpochs/V0.hs
@@ -0,0 +1,92 @@
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE DerivingVia #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE StandaloneDeriving #-}
+{-# LANGUAGE TypeApplications #-}
+{-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE UndecidableInstances #-}
+{-# OPTIONS_GHC -Wno-orphans #-}
+
+module Cardano.Ledger.CanonicalState.Namespace.EntitiesDormantEpochs.V0 (
+  EntitiesDormantEpochsIn (..),
+  EntitiesDormantEpochsOut (..),
+) where
+
+import Cardano.Ledger.BaseTypes (EpochNo)
+import Cardano.Ledger.CanonicalState.Namespace (Era, NamespaceEra)
+import Cardano.SCLS.CBOR.Canonical.Decoder (FromCanonicalCBOR (..))
+import Cardano.SCLS.CBOR.Canonical.Encoder (ToCanonicalCBOR (..))
+import Cardano.SCLS.Entry.IsKey (IsKey (..))
+import Cardano.SCLS.NamespaceCodec (
+  CanonicalCBOREntryDecoder (..),
+  CanonicalCBOREntryEncoder (..),
+  KnownNamespace (..),
+  NamespaceKeySize,
+  namespaceKeySize,
+ )
+import Cardano.SCLS.Versioned (Versioned (..))
+import Data.MemPack (MemPack (packM, unpackM))
+import Data.Proxy (Proxy (..))
+import Data.Word (Word8)
+import GHC.Generics (Generic)
+
+instance
+  ( Era era
+  , NamespaceEra "entities/dormant_epochs/v0" ~ era
+  , ToCanonicalCBOR "entities/dormant_epochs/v0" EntitiesDormantEpochsOut
+  , FromCanonicalCBOR "entities/dormant_epochs/v0" EntitiesDormantEpochsOut
+  ) =>
+  KnownNamespace "entities/dormant_epochs/v0"
+  where
+  type NamespaceKey "entities/dormant_epochs/v0" = EntitiesDormantEpochsIn
+  type NamespaceEntry "entities/dormant_epochs/v0" = EntitiesDormantEpochsOut
+
+instance
+  ( Era era
+  , NamespaceEra "entities/dormant_epochs/v0" ~ era
+  , ToCanonicalCBOR "entities/dormant_epochs/v0" EntitiesDormantEpochsOut
+  ) =>
+  CanonicalCBOREntryEncoder "entities/dormant_epochs/v0" EntitiesDormantEpochsOut
+  where
+  encodeEntry = toCanonicalCBOR (Proxy @"entities/dormant_epochs/v0")
+
+instance
+  ( Era era
+  , NamespaceEra "entities/dormant_epochs/v0" ~ era
+  , FromCanonicalCBOR "entities/dormant_epochs/v0" EntitiesDormantEpochsOut
+  ) =>
+  CanonicalCBOREntryDecoder "entities/dormant_epochs/v0" EntitiesDormantEpochsOut
+  where
+  decodeEntry = fromCanonicalCBOR
+
+data EntitiesDormantEpochsIn = EntitiesDormantEpochsIn
+  deriving (Eq, Ord, Show, Enum, Generic)
+
+type instance NamespaceKeySize "entities/dormant_epochs/v0" = 1
+
+instance IsKey EntitiesDormantEpochsIn where
+  keySize = namespaceKeySize @"entities/dormant_epochs/v0"
+  packKeyM =
+    packM . fromIntegral @_ @Word8 . fromEnum
+  unpackKeyM =
+    toEnum . fromIntegral @Word8 @Int <$> unpackM
+
+newtype EntitiesDormantEpochsOut
+  = EntitiesDormantEpochsOut EpochNo
+  deriving (Eq, Show, Generic)
+
+deriving newtype instance
+  ToCanonicalCBOR "entities/dormant_epochs/v0" EpochNo =>
+  ToCanonicalCBOR "entities/dormant_epochs/v0" EntitiesDormantEpochsOut
+
+deriving newtype instance
+  FromCanonicalCBOR "entities/dormant_epochs/v0" EpochNo =>
+  FromCanonicalCBOR "entities/dormant_epochs/v0" EntitiesDormantEpochsOut
diff --git a/libs/cardano-ledger-canonical-state/test/Test/Cardano/Ledger/CanonicalState/Spec.hs b/libs/cardano-ledger-canonical-state/test/Test/Cardano/Ledger/CanonicalState/Spec.hs
index 022bd741414..730dded1687 100644
--- a/libs/cardano-ledger-canonical-state/test/Test/Cardano/Ledger/CanonicalState/Spec.hs
+++ b/libs/cardano-ledger-canonical-state/test/Test/Cardano/Ledger/CanonicalState/Spec.hs
@@ -13,11 +13,12 @@
 
 module Test.Cardano.Ledger.CanonicalState.Spec (spec) where
 
-import Cardano.Ledger.BaseTypes (EpochInterval, NonNegativeInterval, UnitInterval)
+import Cardano.Ledger.BaseTypes (EpochInterval, EpochNo, NonNegativeInterval, UnitInterval)
 import Cardano.Ledger.CanonicalState.BasicTypes (CanonicalExUnits (..))
 import Cardano.Ledger.CanonicalState.Conway ()
 import qualified Cardano.Ledger.CanonicalState.Namespace.Blocks.V0 as Blocks.V0
 import qualified Cardano.Ledger.CanonicalState.Namespace.EntitiesCommittee.V0 as Committee.V0
+import qualified Cardano.Ledger.CanonicalState.Namespace.EntitiesDormantEpochs.V0 as EntitiesDormantEpochs.V0
 import qualified Cardano.Ledger.CanonicalState.Namespace.GovCommittee.V0 as GovCommittee.V0
 import qualified Cardano.Ledger.CanonicalState.Namespace.GovConstitution.V0 as GovConstitution.V0
 import qualified Cardano.Ledger.CanonicalState.Namespace.GovPParams.V0 as GovPParams.V0
@@ -47,6 +48,12 @@ spec = do
       isCanonical @"entities/committee/v0" @Committee.V0.CanonicalCommitteeAuthorization
       validateType @"entities/committee/v0" @Committee.V0.CanonicalCommitteeAuthorization
         "committee_authorization"
+    describe "entities/dormant_epochs/v0" $ do
+      isCanonical @"entities/dormant_epochs/v0" @EpochNo
+      validateType @"entities/dormant_epochs/v0" @EpochNo "epoch_no"
+      isCanonical @"entities/dormant_epochs/v0" @EntitiesDormantEpochs.V0.EntitiesDormantEpochsOut
+      validateType @"entities/dormant_epochs/v0" @EntitiesDormantEpochs.V0.EntitiesDormantEpochsOut
+        "record_entry"
     describe "gov/committee/v0" $ do
       isCanonical @"gov/committee/v0" @GovCommittee.V0.CanonicalCommittee
       validateType @"gov/committee/v0" @GovCommittee.V0.CanonicalCommittee "committee"
@@ -70,6 +77,7 @@ spec = do
     testNS @"blocks/v0"
     testNS @"utxo/v0"
     testNS @"entities/committee/v0"
+    testNS @"entities/dormant_epochs/v0"
     testNS @"gov/constitution/v0"
     testNS @"gov/committee/v0"
     testNS @"gov/pparams/v0"
diff --git a/libs/cardano-ledger-canonical-state/testlib/Test/Cardano/Ledger/Conway/CanonicalState/Arbitrary.hs b/libs/cardano-ledger-canonical-state/testlib/Test/Cardano/Ledger/Conway/CanonicalState/Arbitrary.hs
index 1a2976e75a0..73ab0189f39 100644
--- a/libs/cardano-ledger-canonical-state/testlib/Test/Cardano/Ledger/Conway/CanonicalState/Arbitrary.hs
+++ b/libs/cardano-ledger-canonical-state/testlib/Test/Cardano/Ledger/Conway/CanonicalState/Arbitrary.hs
@@ -12,6 +12,7 @@ import Cardano.Ledger.CanonicalState.Conway (
   fromGovActionState,
   mkCanonicalConstitution,
  )
+import qualified Cardano.Ledger.CanonicalState.Namespace.EntitiesDormantEpochs.V0 as EntitiesDormantEpochs.V0
 import qualified Cardano.Ledger.CanonicalState.Namespace.GovConstitution.V0 as GovConstitution.V0
 import qualified Cardano.Ledger.CanonicalState.Namespace.GovPParams.V0 as GovPParams.V0
 import qualified Cardano.Ledger.CanonicalState.Namespace.GovProposals.V0 as GovProposals.V0
@@ -32,3 +33,6 @@ instance Arbitrary (GovPParams.V0.GovPParamsOut ConwayEra) where
 
 instance Arbitrary (GovProposals.V0.GovProposalOut CanonicalGovActionState) where
   arbitrary = snd . fromGovActionState <$> arbitrary @(GovActionState ConwayEra)
+
+instance Arbitrary EntitiesDormantEpochs.V0.EntitiesDormantEpochsOut where
+  arbitrary = genericArbitraryU