diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,10 @@
+1.6.2
+
+* [Fix `dhall-json` for new `Prelude.JSON.Type`](https://github.com/dhall-lang/dhall-haskell/pull/1631)
+    * Version 13.0.0 of the Prelude caused the `JSON` type to change, which
+      broke `dhall-json`'s support for that type
+    * This release fixes that (and still supports the old `JSON` type)
+
 1.6.1
 
 * [Fix typos in error messages](https://github.com/dhall-lang/dhall-haskell/pull/1595)
diff --git a/dhall-json.cabal b/dhall-json.cabal
--- a/dhall-json.cabal
+++ b/dhall-json.cabal
@@ -1,8 +1,8 @@
 Name: dhall-json
-Version: 1.6.1
+Version: 1.6.2
 Cabal-Version: >=1.8.0.2
 Build-Type: Simple
-Tested-With: GHC == 7.10.3, GHC == 8.4.3, GHC == 8.6.1
+Tested-With: GHC == 8.0.2, GHC == 8.4.3, GHC == 8.6.1
 License: BSD3
 License-File: LICENSE
 Copyright: 2017 Gabriel Gonzalez
@@ -40,11 +40,11 @@
         aeson-yaml                >= 1.0.5    && < 1.1 ,
         bytestring                               < 0.11,
         containers                                     ,
-        dhall                     >= 1.28.0   && < 1.30,
+        dhall                     >= 1.28.0   && < 1.31,
         exceptions                >= 0.8.3    && < 0.11,
         filepath                                 < 1.5 ,
         optparse-applicative      >= 0.14.0.0 && < 0.16,
-        prettyprinter             >= 1.5.1    && < 1.6 ,
+        prettyprinter             >= 1.5.1    && < 1.7 ,
         scientific                >= 0.3.0.0  && < 0.4 ,
         text                      >= 0.11.1.0 && < 1.3 ,
         unordered-containers                     < 0.3 ,
diff --git a/src/Dhall/JSON.hs b/src/Dhall/JSON.hs
--- a/src/Dhall/JSON.hs
+++ b/src/Dhall/JSON.hs
@@ -540,6 +540,47 @@
                     outer _ = Left (Unsupported e)
 
                 outer value
+        Core.Lam _ (Core.Const Core.Type)
+            (Core.Lam _
+                (Core.Record
+                    [ ("array" , Core.Pi _ (Core.App Core.List (V 0)) (V 1))
+                    , ("bool"  , Core.Pi _ Core.Bool (V 1))
+                    , ("double", Core.Pi _ Core.Double (V 1))
+                    , ("integer", Core.Pi _ Core.Integer (V 1))
+                    , ("null"  , V 0)
+                    , ("object", Core.Pi _ (Core.App Core.List (Core.Record [ ("mapKey", Core.Text), ("mapValue", V 0)])) (V 1))
+                    , ("string", Core.Pi _ Core.Text (V 1))
+                    ]
+                )
+                value
+            ) -> do
+                let outer (Core.Field (V 0) "null") = do
+                        return Aeson.Null
+                    outer (Core.App (Core.Field (V 0) "bool") (Core.BoolLit b)) = do
+                        return (Aeson.Bool b)
+                    outer (Core.App (Core.Field (V 0) "array") (Core.ListLit _ xs)) = do
+                        ys <- traverse outer (Foldable.toList xs)
+
+                        return (Aeson.Array (Vector.fromList ys))
+                    outer (Core.App (Core.Field (V 0) "object") (Core.ListLit _ xs)) = do
+                        let inner (Core.RecordLit [("mapKey", Core.TextLit (Core.Chunks [] mapKey)), ("mapValue", mapExpression)]) = do
+                                mapValue <- outer mapExpression
+
+                                return (mapKey, mapValue)
+                            inner _ = Left (Unsupported e)
+
+                        ys <- traverse inner (Foldable.toList xs)
+
+                        return (Aeson.Object (HashMap.fromList ys))
+                    outer (Core.App (Core.Field (V 0) "double") (Core.DoubleLit (DhallDouble n))) = do
+                        return (Aeson.toJSON n)
+                    outer (Core.App (Core.Field (V 0) "integer") (Core.IntegerLit n)) = do
+                        return (Aeson.toJSON n)
+                    outer (Core.App (Core.Field (V 0) "string") (Core.TextLit (Core.Chunks [] text))) = do
+                        return (toJSON text)
+                    outer _ = Left (Unsupported e)
+
+                outer value
         _ -> Left (Unsupported e)
 
 getContents :: Expr s Void -> Maybe (Text, Maybe (Expr s Void))
@@ -943,11 +984,11 @@
           where
             a' = fmap (fmap loop) a
 
-        Core.Combine a b ->
-            Core.Combine a' b'
+        Core.Combine a b c ->
+            Core.Combine a b' c'
           where
-            a' = loop a
             b' = loop b
+            c' = loop c
 
         Core.CombineTypes a b ->
             Core.CombineTypes a' b'
diff --git a/src/Dhall/JSON/Yaml.hs b/src/Dhall/JSON/Yaml.hs
--- a/src/Dhall/JSON/Yaml.hs
+++ b/src/Dhall/JSON/Yaml.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP               #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards   #-}
 
diff --git a/src/Dhall/JSONToDhall.hs b/src/Dhall/JSONToDhall.hs
--- a/src/Dhall/JSONToDhall.hs
+++ b/src/Dhall/JSONToDhall.hs
@@ -225,7 +225,9 @@
 import           Data.Foldable (toList)
 import qualified Data.HashMap.Strict as HM
 import           Data.List ((\\))
+import qualified Data.List as List
 import           Data.Monoid ((<>))
+import qualified Data.Ord as Ord
 import           Data.Scientific (floatingOrInteger, toRealFloat)
 import qualified Data.Sequence as Seq
 import qualified Data.String
@@ -521,7 +523,7 @@
     loop (App D.Optional expr) value
         = D.Some <$> loop expr value
 
-    -- Arbitrary JSON ~> https://prelude.dhall-lang.org/JSON/Type
+    -- Arbitrary JSON ~> https://prelude.dhall-lang.org/JSON/Type (< v13.0.0)
     loop
       (D.Pi _ (D.Const D.Type)
           (D.Pi _
@@ -545,7 +547,14 @@
                               , ("mapValue", outer val                  )
                               ]
 
-                      elements = Seq.fromList (fmap inner (HM.toList o))
+                      elements =
+                          Seq.fromList
+                              (fmap inner
+                                  (List.sortBy
+                                      (Ord.comparing fst)
+                                      (HM.toList o)
+                                  )
+                              )
 
                       elementType
                           | null elements =
@@ -581,6 +590,86 @@
                             , ("bool"  , D.Pi "_" D.Bool "JSON")
                             , ("null"  , "JSON")
                             , ("number", D.Pi "_" D.Double "JSON")
+                            , ("object", D.Pi "_" (D.App D.List (D.Record [ ("mapKey", D.Text), ("mapValue", "JSON")])) "JSON")
+                            , ("string", D.Pi "_" D.Text "JSON")
+                            ]
+                        )
+                        (outer value)
+                    )
+
+          return result
+
+    -- Arbitrary JSON ~> https://prelude.dhall-lang.org/JSON/Type (v13.0.0 <=)
+    loop
+      (D.Pi _ (D.Const D.Type)
+          (D.Pi _
+              (D.Record
+                  [ ("array" , D.Pi _ (D.App D.List (V 0)) (V 1))
+                  , ("bool"  , D.Pi _ D.Bool (V 1))
+                  , ("double", D.Pi _ D.Double (V 1))
+                  , ("integer", D.Pi _ D.Integer (V 1))
+                  , ("null"  , V 0)
+                  , ("object", D.Pi _ (D.App D.List (D.Record [ ("mapKey", D.Text), ("mapValue", V 0)])) (V 1))
+                  , ("string", D.Pi _ D.Text (V 1))
+                  ]
+              )
+              (V 1)
+          )
+      )
+      value = do
+          let outer (A.Object o) =
+                  let inner (key, val) =
+                          D.RecordLit
+                              [ ("mapKey"  , D.TextLit (D.Chunks [] key))
+                              , ("mapValue", outer val                  )
+                              ]
+
+                      elements =
+                          Seq.fromList
+                              (fmap inner
+                                  (List.sortBy
+                                      (Ord.comparing fst)
+                                      (HM.toList o)
+                                  )
+                              )
+
+                      elementType
+                          | null elements =
+                              Just (D.App D.List (D.Record [ ("mapKey", D.Text), ("mapValue", "JSON") ]))
+                          | otherwise =
+                              Nothing
+
+                      keyValues = D.ListLit elementType elements
+
+                  in  (D.App (D.Field "json" "object") keyValues)
+              outer (A.Array a) =
+                  let elements = Seq.fromList (fmap outer (Vector.toList a))
+
+                      elementType
+                          | null elements = Just (D.App D.List "JSON")
+                          | otherwise     = Nothing
+
+                  in  D.App (D.Field "json" "array") (D.ListLit elementType elements)
+              outer (A.String s) =
+                  D.App (D.Field "json" "string") (D.TextLit (D.Chunks [] s))
+              outer (A.Number n) =
+                  case floatingOrInteger n of
+                      Left floating -> D.App (D.Field "json" "double") (D.DoubleLit (DhallDouble floating))
+                      Right integer -> D.App (D.Field "json" "integer") (D.IntegerLit integer)
+              outer (A.Bool b) =
+                  D.App (D.Field "json" "bool") (D.BoolLit b)
+              outer A.Null =
+                  D.Field "json" "null"
+
+          let result =
+                D.Lam "JSON" (D.Const D.Type)
+                    (D.Lam "json"
+                        (D.Record
+                            [ ("array" , D.Pi "_" (D.App D.List "JSON") "JSON")
+                            , ("bool"  , D.Pi "_" D.Bool "JSON")
+                            , ("double", D.Pi "_" D.Double "JSON")
+                            , ("integer", D.Pi "_" D.Integer "JSON")
+                            , ("null"  , "JSON")
                             , ("object", D.Pi "_" (D.App D.List (D.Record [ ("mapKey", D.Text), ("mapValue", "JSON")])) "JSON")
                             , ("string", D.Pi "_" D.Text "JSON")
                             ]
diff --git a/tasty/Main.hs b/tasty/Main.hs
--- a/tasty/Main.hs
+++ b/tasty/Main.hs
@@ -31,11 +31,15 @@
     Test.Tasty.testGroup "dhall-json"
         [ testDhallToJSON "./tasty/data/issue48"
         , testDhallToJSON "./tasty/data/emptyObjectStrongType"
+        , testDhallToJSON "./tasty/data/toArbitraryJSON_12_0_0"
+        , testDhallToJSON "./tasty/data/toArbitraryJSON_13_0_0"
         , testJSONToDhall "./tasty/data/emptyAlternative"
         , testJSONToDhall "./tasty/data/emptyObject"
         , testJSONToDhall "./tasty/data/emptyList"
         , testJSONToDhall "./tasty/data/emptyObjectStrongType"
         , testJSONToDhall "./tasty/data/emptyListStrongType"
+        , testJSONToDhall "./tasty/data/fromArbitraryJSON_12_0_0"
+        , testJSONToDhall "./tasty/data/fromArbitraryJSON_13_0_0"
         , testCustomConversionJSONToDhall omissibleLists "./tasty/data/missingList"
         , Test.Tasty.testGroup "Nesting"
             [ testDhallToJSON "./tasty/data/nesting0"
diff --git a/tasty/data/fromArbitraryJSON_12_0_0.dhall b/tasty/data/fromArbitraryJSON_12_0_0.dhall
new file mode 100644
--- /dev/null
+++ b/tasty/data/fromArbitraryJSON_12_0_0.dhall
@@ -0,0 +1,17 @@
+  λ(JSON : Type)
+→ λ ( json
+    : { array : List JSON → JSON
+      , bool : Bool → JSON
+      , null : JSON
+      , number : Double → JSON
+      , object : List { mapKey : Text, mapValue : JSON } → JSON
+      , string : Text → JSON
+      }
+    )
+→ json.object
+    [ { mapKey = "array", mapValue = json.array ([] : List JSON) }
+    , { mapKey = "bool", mapValue = json.bool False }
+    , { mapKey = "null", mapValue = json.null }
+    , { mapKey = "number", mapValue = json.number 1.0 }
+    , { mapKey = "string", mapValue = json.string "ABC" }
+    ]
diff --git a/tasty/data/fromArbitraryJSON_12_0_0.json b/tasty/data/fromArbitraryJSON_12_0_0.json
new file mode 100644
--- /dev/null
+++ b/tasty/data/fromArbitraryJSON_12_0_0.json
@@ -0,0 +1,7 @@
+{
+  "array": [],
+  "bool": false,
+  "null": null,
+  "number": 1,
+  "string": "ABC"
+}
diff --git a/tasty/data/fromArbitraryJSON_12_0_0Schema.dhall b/tasty/data/fromArbitraryJSON_12_0_0Schema.dhall
new file mode 100644
--- /dev/null
+++ b/tasty/data/fromArbitraryJSON_12_0_0Schema.dhall
@@ -0,0 +1,11 @@
+  ∀(JSON : Type)
+→ ∀ ( json
+    : { array : List JSON → JSON
+      , bool : Bool → JSON
+      , null : JSON
+      , number : Double → JSON
+      , object : List { mapKey : Text, mapValue : JSON } → JSON
+      , string : Text → JSON
+      }
+    )
+→ JSON
diff --git a/tasty/data/fromArbitraryJSON_13_0_0.dhall b/tasty/data/fromArbitraryJSON_13_0_0.dhall
new file mode 100644
--- /dev/null
+++ b/tasty/data/fromArbitraryJSON_13_0_0.dhall
@@ -0,0 +1,19 @@
+  λ(JSON : Type)
+→ λ ( json
+    : { array : List JSON → JSON
+      , bool : Bool → JSON
+      , double : Double → JSON
+      , integer : Integer → JSON
+      , null : JSON
+      , object : List { mapKey : Text, mapValue : JSON } → JSON
+      , string : Text → JSON
+      }
+    )
+→ json.object
+    [ { mapKey = "array", mapValue = json.array ([] : List JSON) }
+    , { mapKey = "bool", mapValue = json.bool False }
+    , { mapKey = "double", mapValue = json.double 1.5 }
+    , { mapKey = "integer", mapValue = json.integer +1 }
+    , { mapKey = "null", mapValue = json.null }
+    , { mapKey = "string", mapValue = json.string "ABC" }
+    ]
diff --git a/tasty/data/fromArbitraryJSON_13_0_0.json b/tasty/data/fromArbitraryJSON_13_0_0.json
new file mode 100644
--- /dev/null
+++ b/tasty/data/fromArbitraryJSON_13_0_0.json
@@ -0,0 +1,8 @@
+{
+  "array": [],
+  "bool": false,
+  "null": null,
+  "double": 1.5,
+  "integer": 1,
+  "string": "ABC"
+}
diff --git a/tasty/data/fromArbitraryJSON_13_0_0Schema.dhall b/tasty/data/fromArbitraryJSON_13_0_0Schema.dhall
new file mode 100644
--- /dev/null
+++ b/tasty/data/fromArbitraryJSON_13_0_0Schema.dhall
@@ -0,0 +1,12 @@
+  ∀(JSON : Type)
+→ ∀ ( json
+    : { array : List JSON → JSON
+      , bool : Bool → JSON
+      , double : Double → JSON
+      , integer : Integer → JSON
+      , null : JSON
+      , object : List { mapKey : Text, mapValue : JSON } → JSON
+      , string : Text → JSON
+      }
+    )
+→ JSON
diff --git a/tasty/data/toArbitraryJSON_12_0_0.dhall b/tasty/data/toArbitraryJSON_12_0_0.dhall
new file mode 100644
--- /dev/null
+++ b/tasty/data/toArbitraryJSON_12_0_0.dhall
@@ -0,0 +1,17 @@
+  λ(_ : Type)
+→ λ ( _
+    : { array : List _ → _@1
+      , bool : Bool → _@1
+      , null : _
+      , number : Double → _@1
+      , object : List { mapKey : Text, mapValue : _ } → _@1
+      , string : Text → _@1
+      }
+    )
+→ _.object
+    [ { mapKey = "array", mapValue = _.array ([] : List _@1) }
+    , { mapKey = "bool", mapValue = _.bool False }
+    , { mapKey = "null", mapValue = _.null }
+    , { mapKey = "number", mapValue = _.number 1.0 }
+    , { mapKey = "string", mapValue = _.string "ABC" }
+    ]
diff --git a/tasty/data/toArbitraryJSON_12_0_0.json b/tasty/data/toArbitraryJSON_12_0_0.json
new file mode 100644
--- /dev/null
+++ b/tasty/data/toArbitraryJSON_12_0_0.json
@@ -0,0 +1,7 @@
+{
+  "array": [],
+  "bool": false,
+  "null": null,
+  "number": 1,
+  "string": "ABC"
+}
diff --git a/tasty/data/toArbitraryJSON_13_0_0.dhall b/tasty/data/toArbitraryJSON_13_0_0.dhall
new file mode 100644
--- /dev/null
+++ b/tasty/data/toArbitraryJSON_13_0_0.dhall
@@ -0,0 +1,19 @@
+  λ(_ : Type)
+→ λ ( _
+    : { array : List _ → _@1
+      , bool : Bool → _@1
+      , null : _
+      , double : Double → _@1
+      , integer : Integer → _@1
+      , object : List { mapKey : Text, mapValue : _ } → _@1
+      , string : Text → _@1
+      }
+    )
+→ _.object
+    [ { mapKey = "array", mapValue = _.array ([] : List _@1) }
+    , { mapKey = "bool", mapValue = _.bool False }
+    , { mapKey = "null", mapValue = _.null }
+    , { mapKey = "double", mapValue = _.double 1.0 }
+    , { mapKey = "integer", mapValue = _.integer +1 }
+    , { mapKey = "string", mapValue = _.string "ABC" }
+    ]
diff --git a/tasty/data/toArbitraryJSON_13_0_0.json b/tasty/data/toArbitraryJSON_13_0_0.json
new file mode 100644
--- /dev/null
+++ b/tasty/data/toArbitraryJSON_13_0_0.json
@@ -0,0 +1,8 @@
+{
+  "array": [],
+  "bool": false,
+  "null": null,
+  "double": 1,
+  "integer": 1,
+  "string": "ABC"
+}