diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,6 +1,11 @@
 # Changelog for persistent
 
-## 2.12.0.1 (unreleased)
+## 2.12.0.2
+
+* [#1123](https://github.com/yesodweb/persistent/pull/1223)
+    * Fix JSON encoding for `PersistValue`
+
+## 2.12.0.1
 
 * Refactoring token parsing in quasi module [#1206](https://github.com/yesodweb/persistent/pull/1206)
 * Removing duplication from TH output [#1202](https://github.com/yesodweb/persistent/pull/1202)
diff --git a/Database/Persist/Class/PersistField.hs b/Database/Persist/Class/PersistField.hs
--- a/Database/Persist/Class/PersistField.hs
+++ b/Database/Persist/Class/PersistField.hs
@@ -3,7 +3,6 @@
 {-# LANGUAGE ExistentialQuantification #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE PatternGuards, DataKinds, TypeOperators, UndecidableInstances #-}
-{-# OPTIONS_GHC -fno-warn-deprecations #-} -- Pattern match 'PersistDbSpecific'
 module Database.Persist.Class.PersistField
     ( PersistField (..)
     , SomePersistField (..)
@@ -113,9 +112,7 @@
     fromPersistValue (PersistBool b) = Right $ Prelude.show b
     fromPersistValue (PersistList _) = Left $ T.pack "Cannot convert PersistList to String"
     fromPersistValue (PersistMap _) = Left $ T.pack "Cannot convert PersistMap to String"
-    fromPersistValue (PersistDbSpecific _) = Left $ T.pack "Cannot convert PersistDbSpecific to String"
-    fromPersistValue (PersistLiteralEscaped _) = Left $ T.pack "Cannot convert PersistLiteralEscaped to String"
-    fromPersistValue (PersistLiteral _) = Left $ T.pack "Cannot convert PersistLiteral to String"
+    fromPersistValue (PersistLiteral_ _ _) = Left $ T.pack "Cannot convert PersistLiteral_ to String"
     fromPersistValue (PersistArray _) = Left $ T.pack "Cannot convert PersistArray to String"
     fromPersistValue (PersistObjectId _) = Left $ T.pack "Cannot convert PersistObjectId to String"
 #endif
diff --git a/Database/Persist/Sql/Class.hs b/Database/Persist/Sql/Class.hs
--- a/Database/Persist/Sql/Class.hs
+++ b/Database/Persist/Sql/Class.hs
@@ -1135,12 +1135,12 @@
 -- @
 -- import qualified Data.UUID as UUID
 -- instance 'PersistField' UUID where
---   'toPersistValue' = 'PersistDbSpecific' . toASCIIBytes
---   'fromPersistValue' ('PersistDbSpecific' uuid) =
+--   'toPersistValue' = 'PersistLiteralEncoded' . toASCIIBytes
+--   'fromPersistValue' ('PersistLiteralEncoded' uuid) =
 --     case fromASCIIBytes uuid of
 --       'Nothing' -> 'Left' $ "Model/CustomTypes.hs: Failed to deserialize a UUID; received: " <> T.pack (show uuid)
 --       'Just' uuid' -> 'Right' uuid'
---   'fromPersistValue' x = Left $ "File.hs: When trying to deserialize a UUID: expected PersistDbSpecific, received: "-- >  <> T.pack (show x)
+--   'fromPersistValue' x = Left $ "File.hs: When trying to deserialize a UUID: expected PersistLiteralEncoded, received: "-- >  <> T.pack (show x)
 --
 -- instance 'PersistFieldSql' UUID where
 --   'sqlType' _ = 'SqlOther' "uuid"
diff --git a/Database/Persist/Types/Base.hs b/Database/Persist/Types/Base.hs
--- a/Database/Persist/Types/Base.hs
+++ b/Database/Persist/Types/Base.hs
@@ -637,9 +637,7 @@
 fromPersistValueText (PersistMap _) = Left "Cannot convert PersistMap to Text"
 fromPersistValueText (PersistObjectId _) = Left "Cannot convert PersistObjectId to Text"
 fromPersistValueText (PersistArray _) = Left "Cannot convert PersistArray to Text"
-fromPersistValueText (PersistDbSpecific _) = Left "Cannot convert PersistDbSpecific to Text"
-fromPersistValueText (PersistLiteral _) = Left "Cannot convert PersistLiteral to Text"
-fromPersistValueText (PersistLiteralEscaped _) = Left "Cannot convert PersistLiteralEscaped to Text"
+fromPersistValueText (PersistLiteral_ _ _) = Left "Cannot convert PersistLiteral to Text"
 
 instance A.ToJSON PersistValue where
     toJSON (PersistText t) = A.String $ T.cons 's' t
@@ -654,9 +652,15 @@
     toJSON PersistNull = A.Null
     toJSON (PersistList l) = A.Array $ V.fromList $ map A.toJSON l
     toJSON (PersistMap m) = A.object $ map (second A.toJSON) m
-    toJSON (PersistDbSpecific b) = A.String $ T.cons 'p' $ TE.decodeUtf8 $ B64.encode b
-    toJSON (PersistLiteral b) = A.String $ T.cons 'l' $ TE.decodeUtf8 $ B64.encode b
-    toJSON (PersistLiteralEscaped b) = A.String $ T.cons 'e' $ TE.decodeUtf8 $ B64.encode b
+    toJSON (PersistLiteral_ litTy b) =
+        let encoded = TE.decodeUtf8 $ B64.encode b
+            prefix =
+                case litTy of
+                    DbSpecific -> 'p'
+                    Unescaped -> 'l'
+                    Escaped -> 'e'
+         in
+            A.String $ T.cons prefix encoded
     toJSON (PersistArray a) = A.Array $ V.fromList $ map A.toJSON a
     toJSON (PersistObjectId o) =
       A.toJSON $ showChar 'o' $ showHexLen 8 (bs2i four) $ showHexLen 16 (bs2i eight) ""
diff --git a/persistent.cabal b/persistent.cabal
--- a/persistent.cabal
+++ b/persistent.cabal
@@ -1,5 +1,5 @@
 name:            persistent
-version:         2.12.0.1
+version:         2.12.0.2
 license:         MIT
 license-file:    LICENSE
 author:          Michael Snoyman <michael@snoyman.com>
@@ -32,7 +32,7 @@
                    , resourcet                >= 1.1.10
                    , scientific
                    , silently
-                   , template-haskell         >= 2.11
+                   , template-haskell         >= 2.11 && < 2.17
                    , text                     >= 1.2
                    , time                     >= 1.6
                    , transformers             >= 0.5
diff --git a/test/main.hs b/test/main.hs
--- a/test/main.hs
+++ b/test/main.hs
@@ -18,6 +18,8 @@
 #endif
 import Data.Time
 import Text.Shakespeare.Text
+import Data.Aeson
+import qualified Data.ByteString.Char8 as BS8
 
 import Database.Persist.Class.PersistField
 import Database.Persist.Quasi
@@ -869,6 +871,34 @@
             it "works with format" $
                 fromPersistValue (PersistText "2018-02-27 10:49:42.123")
                     `shouldBe` Right (UTCTime (fromGregorian 2018 02 27) (timeOfDayToTime (TimeOfDay 10 49 42.123)))
+
+    describe "PersistValue" $ do
+        describe "Aeson" $ do
+            let
+                testPrefix constr prefixChar bytes =
+                    takePrefix (toJSON (constr (BS8.pack bytes)))
+                    ===
+                    String (T.singleton prefixChar)
+                roundTrip constr bytes =
+                    fromJSON (toJSON (constr (BS8.pack bytes)))
+                    ===
+                    Data.Aeson.Success (constr (BS8.pack bytes))
+                subject constr prefixChar = do
+                    prop ("encodes with a " ++ [prefixChar] ++ " prefix") $
+                        testPrefix constr prefixChar
+                    prop "Round Trips" $
+                        roundTrip constr
+
+            describe "PersistDbSpecific" $ do
+                subject PersistDbSpecific 'p'
+            describe "PersistLiteral" $ do
+                subject PersistLiteral 'l'
+            describe "PersistLiteralEscaped" $ do
+                subject PersistLiteralEscaped 'e'
+
+takePrefix :: Value -> Value
+takePrefix (String a) = String (T.take 1 a)
+takePrefix a = a
 
 asTokens :: [T.Text] -> [Token]
 asTokens = fmap Token