diff --git a/eras/mary/impl/src/Cardano/Ledger/Mary/Value.hs b/eras/mary/impl/src/Cardano/Ledger/Mary/Value.hs
index 2c4f737eeea..00449b98267 100644
--- a/eras/mary/impl/src/Cardano/Ledger/Mary/Value.hs
+++ b/eras/mary/impl/src/Cardano/Ledger/Mary/Value.hs
@@ -135,14 +135,27 @@ instance DecCBOR AssetName where
 
 -- | Policy ID
 newtype PolicyID c = PolicyID {policyID :: ScriptHash c}
-  deriving (Show, Eq, EncCBOR, DecCBOR, Ord, NoThunks, NFData, Generic)
+  deriving
+    ( Show
+    , Eq
+    , Ord
+    , Generic
+    , NoThunks
+    , NFData
+    , EncCBOR
+    , DecCBOR
+    , ToJSON
+    , FromJSON
+    , ToJSONKey
+    , FromJSONKey
+    )
 
 -- | The MultiAssets map
 newtype MultiAsset c = MultiAsset (Map (PolicyID c) (Map AssetName Integer))
   deriving (Show, Generic, ToJSON)
 
 instance Crypto c => Eq (MultiAsset c) where
-  (MultiAsset x) == (MultiAsset y) = pointWise (pointWise (==)) x y
+  MultiAsset x == MultiAsset y = pointWise (pointWise (==)) x y
 
 instance NFData (MultiAsset cypto) where
   rnf (MultiAsset m) = rnf m
@@ -150,8 +163,8 @@ instance NFData (MultiAsset cypto) where
 instance NoThunks (MultiAsset c)
 
 instance Semigroup (MultiAsset c) where
-  (MultiAsset m) <> (MultiAsset m1) =
-    MultiAsset (canonicalMapUnion (canonicalMapUnion (+)) m m1)
+  MultiAsset m1 <> MultiAsset m2 =
+    MultiAsset (canonicalMapUnion (canonicalMapUnion (+)) m1 m2)
 
 instance Monoid (MultiAsset c) where
   mempty = MultiAsset mempty
@@ -179,8 +192,8 @@ instance NFData (MaryValue c) where
 instance NoThunks (MaryValue c)
 
 instance Semigroup (MaryValue c) where
-  MaryValue c m <> MaryValue c1 m1 =
-    MaryValue (c + c1) (m <> m1)
+  MaryValue c1 m1 <> MaryValue c2 m2 =
+    MaryValue (c1 + c2) (m1 <> m2)
 
 instance Monoid (MaryValue c) where
   mempty = MaryValue 0 mempty
@@ -398,14 +411,6 @@ instance ToJSON AssetName where
 instance ToJSONKey AssetName where
   toJSONKey = toJSONKeyText assetNameToTextAsHex
 
-instance ToJSON (PolicyID era) where
-  toJSON (PolicyID (ScriptHash h)) = Aeson.String (Hash.hashToTextAsHex h)
-
-instance ToJSONKey (PolicyID era) where
-  toJSONKey = toJSONKeyText render
-    where
-      render (PolicyID (ScriptHash h)) = Hash.hashToTextAsHex h
-
 -- ========================================================================
 -- Compactible
 -- This is used in the TxOut which stores the (CompactForm MaryValue).
diff --git a/eras/shelley/impl/CHANGELOG.md b/eras/shelley/impl/CHANGELOG.md
index ac907e312b1..9b287aa83c5 100644
--- a/eras/shelley/impl/CHANGELOG.md
+++ b/eras/shelley/impl/CHANGELOG.md
@@ -27,6 +27,7 @@
   * `AccountState`, `EpochState`, `UTxOState`, `IncrementalStake` and `LedgerState`
   * `Likelihood` and `NonMyopic`
   * `RewardUpdate` and `PulsingRewUpdate`
+* Added of `ToJSON`/`FromJSON` instances for `LogWeight`
 
 ### `testlib`