diff --git a/package-lock.json b/package-lock.json
index 890bdc2..698eb04 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,39 @@
 {
+  "name": "purescript-aeson",
+  "lockfileVersion": 2,
   "requires": true,
-  "lockfileVersion": 1,
+  "packages": {
+    "": {
+      "dependencies": {
+        "@mlabs-haskell/json-bigint": "^1.0.0",
+        "big-integer": "^1.6.51"
+      }
+    },
+    "node_modules/@mlabs-haskell/json-bigint": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/@mlabs-haskell/json-bigint/-/json-bigint-1.0.0.tgz",
+      "integrity": "sha512-Opo07yXP/OU9mIoGmY5VVuDy5kxmb3fBAG3U9dbC15qK1OCpVLJAlxbdOfBmLOja94SnIfZINUU2xvYtVfk65w==",
+      "dependencies": {
+        "bignumber.js": "^9.0.0"
+      }
+    },
+    "node_modules/big-integer": {
+      "version": "1.6.51",
+      "resolved": "https://registry.npmjs.org/big-integer/-/big-integer-1.6.51.tgz",
+      "integrity": "sha512-GPEid2Y9QU1Exl1rpO9B2IPJGHPSupF5GnVIP0blYvNOMer2bTvSWs1jGOUg04hTmu67nmLsQ9TBo1puaotBHg==",
+      "engines": {
+        "node": ">=0.6"
+      }
+    },
+    "node_modules/bignumber.js": {
+      "version": "9.1.1",
+      "resolved": "https://registry.npmjs.org/bignumber.js/-/bignumber.js-9.1.1.tgz",
+      "integrity": "sha512-pHm4LsMJ6lzgNGVfZHjMoO8sdoRhOzOH4MLmY65Jg70bpxCKu5iOHNJyfF6OyvYw7t8Fpf35RuzUyqnQsj8Vig==",
+      "engines": {
+        "node": "*"
+      }
+    }
+  },
   "dependencies": {
     "@mlabs-haskell/json-bigint": {
       "version": "1.0.0",
@@ -10,6 +43,11 @@
         "bignumber.js": "^9.0.0"
       }
     },
+    "big-integer": {
+      "version": "1.6.51",
+      "resolved": "https://registry.npmjs.org/big-integer/-/big-integer-1.6.51.tgz",
+      "integrity": "sha512-GPEid2Y9QU1Exl1rpO9B2IPJGHPSupF5GnVIP0blYvNOMer2bTvSWs1jGOUg04hTmu67nmLsQ9TBo1puaotBHg=="
+    },
     "bignumber.js": {
       "version": "9.1.1",
       "resolved": "https://registry.npmjs.org/bignumber.js/-/bignumber.js-9.1.1.tgz",
diff --git a/package.json b/package.json
index ecbaec3..589c187 100644
--- a/package.json
+++ b/package.json
@@ -1,5 +1,6 @@
 {
   "dependencies": {
-    "@mlabs-haskell/json-bigint": "^1.0.0"
+    "@mlabs-haskell/json-bigint": "^1.0.0",
+    "big-integer": "^1.6.51"
   }
 }
diff --git a/packages.dhall b/packages.dhall
index c4753bb..2837f27 100644
--- a/packages.dhall
+++ b/packages.dhall
@@ -105,8 +105,8 @@ in  upstream
 -------------------------------
 -}
 let upstream =
-      https://github.com/purescript/package-sets/releases/download/psc-0.14.5-20211116/packages.dhall
-        sha256:7ba810597a275e43c83411d2ab0d4b3c54d0b551436f4b1632e9ff3eb62e327a
+      https://github.com/purescript/package-sets/releases/download/psc-0.15.4-20230105/packages.dhall
+        sha256:3e9fbc9ba03e9a1fcfd895f65e2d50ee2f5e86c4cd273f3d5c841b655a0e1bda
 
 let additions =
       { sequences =
@@ -129,8 +129,8 @@ let additions =
           , "unfoldable"
           , "unsafe-coerce"
           ]
-        , repo = "https://github.com/hdgarrood/purescript-sequences"
-        , version = "v3.0.2"
+        , repo = "https://github.com/garganscript/purescript-sequences"
+        , version = "cae456c1a7463785ad33981a93e7a9cb5fc7872c"
         }
       , mote =
         { dependencies = [ "these", "transformers", "arrays" ]
@@ -149,9 +149,9 @@ let additions =
           , "prelude"
           , "tuples"
           ]
-        , repo = "https://github.com/mlabs-haskell/purescript-bignumber"
-        , version = "705923edd892a3397b90d28ce7db9a7181dcd599"
+        , repo = "https://github.com/errfrom/purescript-bignumber"
+        , version = "9b3179ad07428d189e42a7a205aab9c7c4849d4a"
         }
       }
 
-in upstream // additions
+in  upstream // additions
diff --git a/src/Aeson.js b/src/Aeson.js
index a4b39b4..fe7bdca 100644
--- a/src/Aeson.js
+++ b/src/Aeson.js
@@ -1,18 +1,18 @@
-const {BigNumber} = require("bignumber.js")
+import BigNumber from "bignumber.js";
 
-const JSONbig = require("@mlabs-haskell/json-bigint")({})
+import JSONbig from "@mlabs-haskell/json-bigint";
 
 //---
 
 const identity = x => x
-exports.fromBoolean = identity
-exports.fromString = identity
-exports.fromFiniteBigNumber = identity
-exports.fromArray = identity
-exports.fromObject = identity
-exports.aesonNull = null
-
-const _caseAeson =
+export const fromBoolean = identity
+export const fromString = identity
+export const fromFiniteBigNumber = identity
+export const fromArray = identity
+export const fromObject = identity
+export const aesonNull = null
+
+export const _caseAeson =
     caseNull =>
     caseBoolean =>
     caseBigNumber =>
@@ -41,7 +41,6 @@ const _caseAeson =
         throw "Imposible happened: JSON object is incorrect: "
             + json.toString() + " " + typeof json;
     }
-exports._caseAeson = _caseAeson
 
 // Hack zone.
 // BigNumberFixed is instanceof BigNumber but
@@ -104,16 +103,17 @@ const traverseFormattingBigNumber = json => {
     return result
 }
 
-exports.stringifyAeson = json => JSONbig.stringify(traverseFormattingBigNumber(json))
+export function stringifyAeson(json) {
+    return JSONbig.stringify(traverseFormattingBigNumber(json));
+}
 
-exports.parseAeson = Nothing => Just => jsonStr => {
+export const parseAeson = Nothing => Just => jsonStr => {
     try {
         return Just(JSONbig.parse(jsonStr))
     } catch (err) {
         return Nothing
     }
 }
-
 // ---
 
 const constant = x => _ => x
@@ -135,13 +135,13 @@ const arrEq = (a, b) =>{
     // Loop here is better than something like:
     //
     // return Array.from(a)
-    //   .reduce((acc, ai, i) => acc && aesonEq(ai, b[i]), true)
+    //   .reduce((acc, ai, i) => acc && aesonEqUncurried(ai, b[i]), true)
     //
     // ... because it allows us to fail fast
     // arrays are not equal
     // as soon as we encounter first inequality
     for (let i = 0; i < a.length; i++)
-        if (!aesonEq(a[i], b[i]))
+        if (!aesonEqUncurried(a[i], b[i]))
             return false
 
     // Are you still here?
@@ -167,7 +167,7 @@ const objectEq = (a, b) => {
 
     for (let i = 0; i < aKeys.length; i++) {
         let key = aKeys[i]
-        if (!aesonEq(a[key], b[key]))
+        if (!aesonEqUncurried(a[key], b[key]))
             return false
     }
 
@@ -190,7 +190,7 @@ const typeOf = _caseAeson
     (constant(tArr))
     (constant(tObj))
 
-const aesonEq = (a, b) => {
+const aesonEqUncurried = (a, b) => {
     // If "constructors" are different
     // aesons are not equal
     const tOfA = typeOf(a)
@@ -209,4 +209,6 @@ const aesonEq = (a, b) => {
     throw "Imposible happened: Unexpected type of JSON: " + a.toString
 }
 
-exports.aesonEq = a => b => aesonEq(a, b)
+export function aesonEq(a) {
+    return b => aesonEqUncurried(a, b);
+}
diff --git a/src/Aeson.purs b/src/Aeson.purs
index 5a1d5e3..624b1ba 100644
--- a/src/Aeson.purs
+++ b/src/Aeson.purs
@@ -103,11 +103,12 @@ import Data.Argonaut (JsonDecodeError(..), printJsonDecodeError) as DataArgonaut
 import Data.Argonaut (fromArray, fromObject, jsonNull) as Argonaut
 import Data.Argonaut.Encode.Encoders (encodeBoolean, encodeString)
 import Data.Array (cons, fromFoldable, head, length, tail, toUnfoldable, (!!))
-import Data.Bifunctor (lmap)
+import Data.Bifunctor (lmap, rmap)
 import Data.BigInt (BigInt)
 import Data.BigInt as BigInt
 import Data.BigNumber (BigNumber, isInteger)
 import Data.BigNumber as BigNumber
+import Data.Bitraversable (rtraverse)
 import Data.Either (Either(Right, Left), fromRight, note)
 import Data.Foldable (foldM, intercalate)
 import Data.Int as Int
@@ -672,7 +673,8 @@ instance (Ord a, DecodeAeson a) => DecodeAeson (Set a) where
   decodeAeson x = Set.fromFoldable <$> (decodeAeson x :: _ (Array _))
 
 instance (Ord k, DecodeAeson k, DecodeAeson v) => DecodeAeson (Map k v) where
-  decodeAeson x = Map.fromFoldable <$> (decodeAeson x :: _ (Array _))
+  decodeAeson x = Map.fromFoldable <$>
+    (traverse (rtraverse decodeAeson) =<< (decodeAeson x :: _ (Array (Tuple k Aeson))))
 
 instance DecodeAeson a => DecodeAeson (Maybe a) where
   decodeAeson aeson =
@@ -818,7 +820,7 @@ else instance
   , EncodeAeson b
   ) =>
   EncodeTupleAux (Tuple a b) where
-  tupleToArray (Tuple a b) = [ encodeAeson a, encodeAeson b ]
+    tupleToArray (Tuple a b) = [ encodeAeson a, encodeAeson b ]
 
 instance EncodeTupleAux (Tuple a b) => EncodeAeson (Tuple a b) where
   -- Encodes nested tuple of arbitrary size, (like Boolean /\ Boolean /\ Boolean /\ ...)
@@ -840,7 +842,7 @@ instance (EncodeAeson a) => EncodeAeson (Set a) where
   encodeAeson x = encodeAeson $ (Set.toUnfoldable x :: Array _)
 
 instance (EncodeAeson k, EncodeAeson v) => EncodeAeson (Map k v) where
-  encodeAeson x = encodeAeson $ (Map.toUnfoldable x :: Array _)
+  encodeAeson x = encodeAeson $ map (rmap encodeAeson) (Map.toUnfoldable x :: Array _)
 
 instance EncodeAeson a => EncodeAeson (Maybe a) where
   encodeAeson Nothing = aesonNull
diff --git a/test/Gen.purs b/test/Gen.purs
index e54841e..410f5ef 100644
--- a/test/Gen.purs
+++ b/test/Gen.purs
@@ -6,11 +6,11 @@ import Aeson (Aeson, Finite, aesonNull, finiteBigNumber, fromArray, fromBoolean,
 import Control.Lazy (defer, fix)
 import Data.Argonaut (Json)
 import Data.Argonaut.Gen (genJson)
+import Data.Array.NonEmpty as LNA
 import Data.BigNumber (BigNumber)
 import Data.BigNumber as BigNumber
 import Data.Either (fromRight)
 import Data.Int as Int
-import Data.List.NonEmpty as LNE
 import Data.Maybe (fromJust, maybe)
 import Data.String as S
 import Data.Tuple (Tuple(Tuple))
@@ -22,7 +22,7 @@ import Test.QuickCheck (arbitrary)
 import Test.QuickCheck.Gen (Gen, chooseInt, frequency, resize, sized, vectorOf)
 
 frequency' :: Partial => forall a. Array (Tuple Number (Gen a)) -> Gen a
-frequency' = frequency <<< fromJust <<< LNE.fromFoldable
+frequency' = frequency <<< fromJust <<< LNA.fromFoldable
 
 oneOf :: forall a. Partial => Array (Gen a) -> Gen a
 oneOf arr = frequency' $ Tuple 1.0 <$> arr