diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,15 @@
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## 1.0.4 - 2022-05-15
+
+### Fixed
+- Remove `Arbitrary Value` instance because it is already provided by the `aeson` package.
+
+### Changed
+- Relax restrictions on `params` field for JSON-RPCv1 requests.
+- Bump minimum version of `aeson` accordingly.
+
 ## 1.0.3 - 2020-06-19
 
 ### Changed
diff --git a/json-rpc.cabal b/json-rpc.cabal
--- a/json-rpc.cabal
+++ b/json-rpc.cabal
@@ -1,13 +1,13 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.33.0.
+-- This file has been generated from package.yaml by hpack version 0.34.4.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 77cd2980380a86ce6731e9afcae7c2ecc42257843e71231bcebaba6929bee5c8
+-- hash: 4e2a99d4fdf85a19844c7bf16c14016bfd147baa005a628bebb4ea97823c379c
 
 name:           json-rpc
-version:        1.0.3
+version:        1.0.4
 synopsis:       Fully-featured JSON-RPC 2.0 library
 description:    Please see the README on GitHub at <https://github.com/jprupp/json-rpc#readme>
 category:       Network
@@ -39,7 +39,7 @@
   ghc-options: -Wall
   build-depends:
       QuickCheck
-    , aeson
+    , aeson >=2.0.3.0
     , attoparsec
     , base >=4.6 && <5
     , bytestring
@@ -63,7 +63,7 @@
       Paths_json_rpc
   build-depends:
       QuickCheck
-    , aeson
+    , aeson >=2.0.3.0
     , base >=4.6 && <5
     , bytestring
     , conduit
@@ -85,7 +85,7 @@
       Paths_json_rpc
   build-depends:
       QuickCheck
-    , aeson
+    , aeson >=2.0.3.0
     , base >=4.6 && <5
     , bytestring
     , conduit
@@ -107,7 +107,7 @@
       Paths_json_rpc
   build-depends:
       QuickCheck
-    , aeson
+    , aeson >=2.0.3.0
     , base >=4.6 && <5
     , bytestring
     , conduit
@@ -129,7 +129,7 @@
       Paths_json_rpc
   build-depends:
       QuickCheck
-    , aeson
+    , aeson >=2.0.3.0
     , base >=4.6 && <5
     , bytestring
     , conduit
@@ -155,7 +155,7 @@
   ghc-options: -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       QuickCheck
-    , aeson
+    , aeson >=2.0.3.0
     , base >=4.6 && <5
     , bytestring
     , conduit
diff --git a/src/Network/JSONRPC/Arbitrary.hs b/src/Network/JSONRPC/Arbitrary.hs
--- a/src/Network/JSONRPC/Arbitrary.hs
+++ b/src/Network/JSONRPC/Arbitrary.hs
@@ -2,8 +2,6 @@
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 module Network.JSONRPC.Arbitrary where
 
-import           Data.Aeson.Types
-import qualified Data.HashMap.Strict       as M
 import           Data.Text                 (Text)
 import qualified Data.Text                 as T
 import           Network.JSONRPC.Data
@@ -61,20 +59,4 @@
 
 instance Arbitrary Id where
     arbitrary = IdInt <$> arbitraryBoundedRandom
-
-instance Arbitrary Value where
-    arbitrary = resize 10 $ oneof [nonull, lsn, objn] where
-        nonull = oneof
-            [ toJSON <$> (arbitrary :: Gen String)
-            , toJSON <$> (arbitrary :: Gen Int)
-            , toJSON <$> (arbitrary :: Gen Double)
-            , toJSON <$> (arbitrary :: Gen Bool)
-            ]
-        val = oneof [ nonull, return Null ]
-        ls   = toJSON <$> listOf val
-        obj  = toJSON . M.fromList <$> listOf ps
-        ps   = (,) <$> (arbitrary :: Gen String) <*> oneof [val, ls]
-        lsn  = toJSON <$> listOf (oneof [ls, obj, val])
-        objn = toJSON . M.fromList <$> listOf psn
-        psn  = (,) <$> (arbitrary :: Gen String) <*> oneof [val, ls, obj]
 
diff --git a/src/Network/JSONRPC/Data.hs b/src/Network/JSONRPC/Data.hs
--- a/src/Network/JSONRPC/Data.hs
+++ b/src/Network/JSONRPC/Data.hs
@@ -78,15 +78,13 @@
     toJSON (Request V2 m p i) = object $ case p of
         Null -> [jr2, "method" .= m, "id" .= i]
         _    -> [jr2, "method" .= m, "id" .= i, "params" .= p]
-    toJSON (Request V1 m p i) = object $ case p of
-        Null -> ["method" .= m, "params" .= emptyArray, "id" .= i]
-        _    -> ["method" .= m, "params" .= p, "id" .= i]
+    toJSON (Request V1 m p i) =
+        object ["method" .= m, "params" .= p, "id" .= i]
     toJSON (Notif V2 m p) = object $ case p of
         Null -> [jr2, "method" .= m]
         _    -> [jr2, "method" .= m, "params" .= p]
-    toJSON (Notif V1 m p) = object $ case p of
-        Null -> ["method" .= m, "params" .= emptyArray, "id" .= Null]
-        _    -> ["method" .= m, "params" .= p, "id" .= Null]
+    toJSON (Notif V1 m p) =
+      object ["method" .= m, "params" .= p, "id" .= Null]
 
 class FromRequest q where
     -- | Parser for params Value in JSON-RPC request.