diff --git a/lerna.json b/lerna.json
index d2a09faff..7fc530bb6 100644
--- a/lerna.json
+++ b/lerna.json
@@ -10,5 +10,5 @@
   "packages": [
     "packages/*"
   ],
-  "version": "0.20.5"
+  "version": "0.21.0"
 }
diff --git a/package.json b/package.json
index 9764f530a..d53cb23c0 100644
--- a/package.json
+++ b/package.json
@@ -11,6 +11,6 @@
     "test": "jest --coverage"
   },
   "devDependencies": {
-    "@polkadot/dev": "^0.19.9"
+    "@polkadot/dev": "^0.19.10"
   }
 }
diff --git a/packages/util-crypto/package.json b/packages/util-crypto/package.json
index 1c80d3e20..ce87275ae 100644
--- a/packages/util-crypto/package.json
+++ b/packages/util-crypto/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@polkadot/util-crypto",
-  "version": "0.20.5",
+  "version": "0.21.0",
   "description": "A collection of useful crypto utilities for @polkadot",
   "main": "index.js",
   "keywords": [
@@ -30,7 +30,7 @@
   },
   "dependencies": {
     "@babel/runtime": "^7.0.0-beta.47",
-    "@polkadot/util": "^0.20.5",
+    "@polkadot/util": "^0.21.0",
     "blakejs": "^1.1.0",
     "js-sha3": "^0.7.0",
     "tweetnacl": "^1.0.0",
diff --git a/packages/util-keyring/package.json b/packages/util-keyring/package.json
index c051cb73c..a159a1450 100644
--- a/packages/util-keyring/package.json
+++ b/packages/util-keyring/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@polkadot/util-keyring",
-  "version": "0.20.5",
+  "version": "0.21.0",
   "description": "Keyring management",
   "main": "index.js",
   "engines": {
@@ -32,8 +32,8 @@
   },
   "dependencies": {
     "@babel/runtime": "^7.0.0-beta.47",
-    "@polkadot/util": "^0.20.5",
-    "@polkadot/util-crypto": "^0.20.5",
+    "@polkadot/util": "^0.21.0",
+    "@polkadot/util-crypto": "^0.21.0",
     "bs58": "^4.0.1"
   }
 }
diff --git a/packages/util-rlp/package.json b/packages/util-rlp/package.json
index 91ae1013b..92e2afa2d 100644
--- a/packages/util-rlp/package.json
+++ b/packages/util-rlp/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@polkadot/util-rlp",
-  "version": "0.20.5",
+  "version": "0.21.0",
   "description": "RLP encoding and decoding",
   "main": "index.js",
   "keywords": [
@@ -30,7 +30,7 @@
   },
   "dependencies": {
     "@babel/runtime": "^7.0.0-beta.47",
-    "@polkadot/util": "^0.20.5"
+    "@polkadot/util": "^0.21.0"
   },
   "devDependencies": {
     "ethereumjs-testing": "^1.0.4"
diff --git a/packages/util-triehash/package.json b/packages/util-triehash/package.json
index 0a69fa43d..6eff9f8b0 100644
--- a/packages/util-triehash/package.json
+++ b/packages/util-triehash/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@polkadot/util-triehash",
-  "version": "0.20.5",
+  "version": "0.21.0",
   "description": "Creation of triehash values",
   "main": "index.js",
   "keywords": [
@@ -30,8 +30,8 @@
   },
   "dependencies": {
     "@babel/runtime": "^7.0.0-beta.47",
-    "@polkadot/util": "^0.20.5",
-    "@polkadot/util-crypto": "^0.20.5",
-    "@polkadot/util-rlp": "^0.20.5"
+    "@polkadot/util": "^0.21.0",
+    "@polkadot/util-crypto": "^0.21.0",
+    "@polkadot/util-rlp": "^0.21.0"
   }
 }
diff --git a/packages/util/docs/README.md b/packages/util/docs/README.md
index 46a8f14ae..3d5171a8f 100644
--- a/packages/util/docs/README.md
+++ b/packages/util/docs/README.md
@@ -8,7 +8,6 @@ Utility methods for this package are split into groups
 - [ext](ext.md) Extensions to basic classes
 - [hex](hex.md) Internal utilities to create and test for hex values
 - [is](is.md) Type checking utilities
-- [jsonrpc](jsonrpc.md) Convenience functions for values from @polkadot/api-jsonrpc
 - [number](number.md) Utility methods to convert to and from `number` values
 - [string](string.md) Utility methods to convert to work with `string` values
 - [u8a](u8a.md) Utility methods to convert to and from `Uint8Array` objects
diff --git a/packages/util/docs/jsonrpc.md b/packages/util/docs/jsonrpc.md
deleted file mode 100644
index 2ce49ec01..000000000
--- a/packages/util/docs/jsonrpc.md
+++ /dev/null
@@ -1,42 +0,0 @@
-# jsonrpc
-
-Convenience functions for values from @polkadot/api-jsonrpc 
-
-- [jsonrpcParam](#jsonrpcparam) Returns a string representation of the parameter name (optional) & type.
-- [jsonrpcSignature](#jsonrpcsignature) Returns a string representation of the method with inputs and outputs.
-
-## jsonrpcParam
-
-Returns a string representation of the parameter name (optional) & type. 
-
-```js
-jsonrpcParam (param: { name?: string, type: string }): string
-```
-
-
-Formats the name and type into a human-readable string.
-
-```js
-import { jsonrpcParam } from '@polkadot/util';
-
-console.log(jsonrpcParam({ name: 'dest', type: 'Address' }); // => dest: Address
-```
-
-## jsonrpcSignature
-
-Returns a string representation of the method with inputs and outputs. 
-
-```js
-jsonrpcSignature (name: string, _inputs: Array<InterfaceInputType>, _output: InterfaceOutputType): string
-```
-
-
-Formats the name, inputs and outputs into a human-readable string. This contains the input parameter names, input types and output type.
-
-```js
-import { jsonrpcSignature } from '@polkadot/util';
-
-console.log(jsonrpcSignature(
-'test_method', [{ name: 'dest', type: 'Address' }], { type: 'Address' }
-)); // => test_method (dest: Address): Address
-```
\ No newline at end of file
diff --git a/packages/util/package.json b/packages/util/package.json
index dec14be8d..83c7830ea 100644
--- a/packages/util/package.json
+++ b/packages/util/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@polkadot/util",
-  "version": "0.20.5",
+  "version": "0.21.0",
   "description": "A collection of useful utilities for @polkadot",
   "main": "index.js",
   "keywords": [
@@ -28,9 +28,6 @@
     "check": "eslint src && flow check",
     "test": "echo \"Tests only available from root wrapper\""
   },
-  "devDependencies": {
-    "@polkadot/api-jsonrpc": "^0.11.2"
-  },
   "dependencies": {
     "@babel/runtime": "^7.0.0-beta.47",
     "bn.js": "^4.11.8",
diff --git a/packages/util/src/index.js b/packages/util/src/index.js
index 660e13665..f03ee3c27 100644
--- a/packages/util/src/index.js
+++ b/packages/util/src/index.js
@@ -10,7 +10,6 @@ const buffer = require('./buffer');
 const ext = require('./ext');
 const hex = require('./hex');
 const is = require('./is');
-const jsonrpc = require('./jsonrpc');
 const logger = require('./logger');
 const number = require('./number');
 const promisify = require('./promisify');
@@ -21,5 +20,5 @@ const u8a = require('./u8a');
   @summary Utility methods for this package are split into groups
 */
 module.exports = Object.assign(
-  {}, array, { assert }, bn, buffer, ext, hex, is, jsonrpc, { logger }, number, { promisify }, string, u8a
+  {}, array, { assert }, bn, buffer, ext, hex, is, { logger }, number, { promisify }, string, u8a
 );
diff --git a/packages/util/src/jsonrpc/index.js b/packages/util/src/jsonrpc/index.js
deleted file mode 100644
index 2fc2e6db5..000000000
--- a/packages/util/src/jsonrpc/index.js
+++ /dev/null
@@ -1,15 +0,0 @@
-// Copyright 2017-2018 Jaco Greeff
-// This software may be modified and distributed under the terms
-// of the ISC license. See the LICENSE file for details.
-// @flow
-
-const jsonrpcParam = require('./param');
-const jsonrpcSignature = require('./signature');
-
-/**
-  @summary Convenience functions for values from @polkadot/api-jsonrpc
-*/
-module.exports = {
-  jsonrpcParam,
-  jsonrpcSignature
-};
diff --git a/packages/util/src/jsonrpc/param.js b/packages/util/src/jsonrpc/param.js
deleted file mode 100644
index 20a093ab7..000000000
--- a/packages/util/src/jsonrpc/param.js
+++ /dev/null
@@ -1,25 +0,0 @@
-// Copyright 2017-2018 Jaco Greeff
-// This software may be modified and distributed under the terms
-// of the ISC license. See the LICENSE file for details.
-// @flow
-
-import type { InterfaceInputType, InterfaceOutputType } from '@polkadot/api-jsonrpc/types';
-
-/**
-  @name jsonrpcParam
-  @signature jsonrpcParam (param: { name?: string, type: string }): string
-  @summary Returns a string representation of the parameter name (optional) & type.
-  @description
-    Formats the name and type into a human-readable string.
-  @example
-    import { jsonrpcParam } from '@polkadot/util';
-
-    console.log(jsonrpcParam({ name: 'dest', type: 'Address' }); // => dest: Address
-*/
-module.exports = function jsonrpcParam (param: InterfaceInputType | InterfaceOutputType): string {
-  // flowlint-next-line sketchy-null-mixed:off,sketchy-null-string:off
-  return param.name
-    // $FlowFixMe InterfaceInputType found, has name
-    ? `${param.name}: ${param.type}`
-    : param.type;
-};
diff --git a/packages/util/src/jsonrpc/param.spec.js b/packages/util/src/jsonrpc/param.spec.js
deleted file mode 100644
index c745cc70c..000000000
--- a/packages/util/src/jsonrpc/param.spec.js
+++ /dev/null
@@ -1,23 +0,0 @@
-// Copyright 2017-2018 Jaco Greeff
-// This software may be modified and distributed under the terms
-// of the ISC license. See the LICENSE file for details.
-
-const { jsonrpcParam } = require('./index');
-
-describe('jsonrpcParam', () => {
-  it('formats input parameters (name & type)', () => {
-    expect(
-      jsonrpcParam(
-        { name: 'b', type: 'A' }
-      )
-    ).toEqual('b: A');
-  });
-
-  it('formats output paramaters (type-only)', () => {
-    expect(
-      jsonrpcParam(
-        { type: 'A' }
-      )
-    ).toEqual('A');
-  });
-});
diff --git a/packages/util/src/jsonrpc/signature.js b/packages/util/src/jsonrpc/signature.js
deleted file mode 100644
index a8b18e993..000000000
--- a/packages/util/src/jsonrpc/signature.js
+++ /dev/null
@@ -1,28 +0,0 @@
-// Copyright 2017-2018 Jaco Greeff
-// This software may be modified and distributed under the terms
-// of the ISC license. See the LICENSE file for details.
-// @flow
-
-import type { InterfaceInputType, InterfaceOutputType } from '@polkadot/api-jsonrpc/types';
-
-const formatParam = require('./param');
-
-/**
-  @name jsonrpcSignature
-  @signature jsonrpcSignature (name: string, _inputs: Array<InterfaceInputType>, _output: InterfaceOutputType): string
-  @summary Returns a string representation of the method with inputs and outputs.
-  @description
-    Formats the name, inputs and outputs into a human-readable string. This contains the input parameter names, input types and output type.
-  @example
-    import { jsonrpcSignature } from '@polkadot/util';
-
-    console.log(jsonrpcSignature(
-      'test_method', [{ name: 'dest', type: 'Address' }], { type: 'Address' }
-    )); // => test_method (dest: Address): Address
-*/
-module.exports = function jsonrpcSignature (name: string, _inputs: Array<InterfaceInputType>, _output: InterfaceOutputType): string {
-  const inputs = _inputs.map(formatParam).join(', ');
-  const output = formatParam(_output);
-
-  return `${name} (${inputs}): ${output}`;
-};
diff --git a/packages/util/src/jsonrpc/signature.spec.js b/packages/util/src/jsonrpc/signature.spec.js
deleted file mode 100644
index 9b80c988f..000000000
--- a/packages/util/src/jsonrpc/signature.spec.js
+++ /dev/null
@@ -1,32 +0,0 @@
-// Copyright 2017-2018 Jaco Greeff
-// This software may be modified and distributed under the terms
-// of the ISC license. See the LICENSE file for details.
-
-const { jsonrpcSignature } = require('./index');
-
-describe('jsonrpcSignature', () => {
-  it('formats the signature according to the specification', () => {
-    expect(
-      jsonrpcSignature(
-        'test_method',
-        [
-          { name: 'b', type: 'A' },
-          { name: 'a', type: 'B' },
-          { type: 'C' },
-          { type: 'D' }
-        ],
-        { type: 'A' }
-      )
-    ).toEqual('test_method (b: A, a: B, C, D): A');
-  });
-
-  it('empty inputs format correctly', () => {
-    expect(
-      jsonrpcSignature(
-        'test_method',
-        [],
-        { type: 'A' }
-      )
-    ).toEqual('test_method (): A');
-  });
-});
diff --git a/yarn.lock b/yarn.lock
index 771d2649b..c92de1f72 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -664,15 +664,9 @@
     lodash "^4.17.5"
     to-fast-properties "^2.0.0"
 
-"@polkadot/api-jsonrpc@^0.11.2":
-  version "0.11.2"
-  resolved "https://registry.yarnpkg.com/@polkadot/api-jsonrpc/-/api-jsonrpc-0.11.2.tgz#f2ddaab686a2da5a63a1a519d76a26d433486927"
-  dependencies:
-    "@babel/runtime" "^7.0.0-beta.47"
-
-"@polkadot/dev@^0.19.9":
-  version "0.19.9"
-  resolved "https://registry.yarnpkg.com/@polkadot/dev/-/dev-0.19.9.tgz#cc37c7364e010d96f45132d0069eda32f52e8462"
+"@polkadot/dev@^0.19.10":
+  version "0.19.10"
+  resolved "https://registry.yarnpkg.com/@polkadot/dev/-/dev-0.19.10.tgz#ccfbfb8632371876456a8e3e89ff26f10b27ba26"
   dependencies:
     "@babel/cli" "^7.0.0-beta.47"
     "@babel/core" "^7.0.0-beta.47"