diff --git a/karma.conf.js b/karma.conf.js
index 82a17b5f..f166a9e5 100644
--- a/karma.conf.js
+++ b/karma.conf.js
@@ -1,6 +1,7 @@
 module.exports = function(config) {
   config.set({
     frameworks: ['mocha', 'karma-typescript'],
+    exclude: ["src/@types/**"],  // ref: https://github.com/monounity/karma-typescript/issues/254
     files: ['src/**/*.ts', 'test/**/*.ts'],
     preprocessors: {
       '**/*.ts': ['karma-typescript'],
diff --git a/src/@types/ethjs-util/index.d.ts b/src/@types/ethjs-util/index.d.ts
new file mode 100644
index 00000000..1b243730
--- /dev/null
+++ b/src/@types/ethjs-util/index.d.ts
@@ -0,0 +1,69 @@
+declare module 'ethjs-util' {
+  /**
+   * @description Returns a `Boolean` on whether or not the a `String` starts with '0x'
+   */
+  export function isHexPrefixed(str: string): boolean
+
+  /**
+   * @description Removes '0x' from a given `String` if present
+   */
+  export function stripHexPrefix(str: string): string
+
+  /**
+   * @description Pads a `String` to have an even length
+   */
+  export function padToEven(value: string): string
+
+  /**
+   * @description Converts a `Number` into a hex `String`
+   */
+  export function intToHex(i: number): string
+
+  /**
+   * @description Converts an `Number` to a `Buffer`
+   */
+  export function intToBuffer(i: number): Buffer
+
+  /**
+   * @description Get the binary size of a string
+   */
+  export function getBinarySize(str: string): number
+
+  /**
+   * @description Returns TRUE if the first specified array contains all elements
+   *              from the second one. FALSE otherwise. If `some` is true, will
+   *              return true if first specified array contain some elements of
+   *              the second.
+   */
+  export function arrayContainsArray(superset: any[], subset: any[], some?: boolean): boolean
+
+  /**
+   * @description Should be called to get utf8 from it's hex representation
+   */
+  export function toUtf8(hex: string): string
+
+  /**
+   * @description Should be called to get ascii from it's hex representation
+   */
+  export function toAscii(hex: string): string
+
+  /**
+   * @description Should be called to get hex representation (prefixed by 0x) of utf8 string
+   */
+  export function fromUtf8(stringValue: string): string
+
+  /**
+   * @description Should be called to get hex representation (prefixed by 0x) of ascii string
+   */
+  export function fromAscii(stringValue: string): string
+
+  /**
+   * @description getKeys([{a: 1, b: 2}, {a: 3, b: 4}], 'a') => [1, 3]
+   */
+  export function getKeys(params: any[], key: string, allowEmpty?: boolean): any[]
+
+  /**
+   * @description check if string is hex string of specific length
+   */
+  export function isHexString(value: string, length?: number): boolean
+}
diff --git a/src/account.ts b/src/account.ts
index 0d1fb63e..00f7bbc9 100644
--- a/src/account.ts
+++ b/src/account.ts
@@ -1,4 +1,4 @@
-const ethjsUtil = require('ethjs-util')
+import * as ethjsUtil from 'ethjs-util'
 import * as assert from 'assert'
 import * as secp256k1 from 'secp256k1'
 import * as BN from 'bn.js'
diff --git a/src/bytes.ts b/src/bytes.ts
index 39634853..94492aa4 100644
--- a/src/bytes.ts
+++ b/src/bytes.ts
@@ -1,4 +1,4 @@
-const ethjsUtil = require('ethjs-util')
+import * as ethjsUtil from 'ethjs-util'
 import * as BN from 'bn.js'
 import { assertIsBuffer, assertIsArray, assertIsHexString } from './helpers'
 
diff --git a/src/externals.ts b/src/externals.ts
index 2e233bdc..01aea919 100644
--- a/src/externals.ts
+++ b/src/externals.ts
@@ -1,19 +1,12 @@
 /**
  * Re-exports commonly used modules:
- * * Adds [`ethjs-util`](https://github.com/ethjs/ethjs-util) methods.
  * * Exports [`BN`](https://github.com/indutny/bn.js), [`rlp`](https://github.com/ethereumjs/rlp).
  * @packageDocumentation
  */
 
-const ethjsUtil = require('ethjs-util')
 import * as BN from 'bn.js'
 import * as rlp from 'rlp'
 
-/**
- * [`ethjsUtil`](https://github.com/ethjs/ethjs-util)
- */
-Object.assign(exports, ethjsUtil)
-
 /**
  * [`BN`](https://github.com/indutny/bn.js)
  */
diff --git a/src/hash.ts b/src/hash.ts
index e9e40ca7..57e06d81 100644
--- a/src/hash.ts
+++ b/src/hash.ts
@@ -1,6 +1,6 @@
 const createKeccakHash = require('keccak')
 const createHash = require('create-hash')
-const ethjsUtil = require('ethjs-util')
+import * as ethjsUtil from 'ethjs-util'
 import * as rlp from 'rlp'
 import { toBuffer, setLengthLeft } from './bytes'
 import { assertIsString, assertIsBuffer, assertIsArray, assertIsHexString } from './helpers'
diff --git a/src/helpers.ts b/src/helpers.ts
index c6959678..e1403366 100644
--- a/src/helpers.ts
+++ b/src/helpers.ts
@@ -1,4 +1,4 @@
-const ethjsUtil = require('ethjs-util')
+import * as ethjsUtil from 'ethjs-util'
 
 /**
  * Throws if a string is not hex prefixed
diff --git a/src/index.ts b/src/index.ts
index 73e913d3..37831e28 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -29,6 +29,11 @@ export * from './bytes'
 export * from './object'
 
 /**
- * External exports (ethjsUtil, BN, rlp, secp256k1)
+ * External exports (BN, rlp, secp256k1)
  */
 export * from './externals'
+
+/**
+ * Export ethjs-util methods
+ */
+export * from 'ethjs-util'
diff --git a/src/object.ts b/src/object.ts
index fb3cb314..e24991eb 100644
--- a/src/object.ts
+++ b/src/object.ts
@@ -1,4 +1,4 @@
-const ethjsUtil = require('ethjs-util')
+import * as ethjsUtil from 'ethjs-util'
 import * as assert from 'assert'
 import * as rlp from 'rlp'
 import { toBuffer, baToJSON, unpadBuffer } from './bytes'
diff --git a/test/externals.spec.ts b/test/externals.spec.ts
index 6d8402ba..1d837c92 100644
--- a/test/externals.spec.ts
+++ b/test/externals.spec.ts
@@ -101,24 +101,24 @@ describe('External ethjsUtil export', () => {
 
   it('should use ethjsUtil functions correctly', () => {
     // should convert intToHex
-    assert.equal((src as any).intToHex(new src.BN(0)), '0x0')
+    assert.equal(src.intToHex(new src.BN(0).toNumber()), '0x0')
 
     // should convert intToHex
     const i = 6003400
-    const hex = (src as any).intToHex(i)
+    const hex = src.intToHex(i)
     assert.equal(hex, '0x5b9ac8')
 
     // should convert a int to a buffer
     const j = 6003400
-    const buf = (src as any).intToBuffer(j)
+    const buf = src.intToBuffer(j)
     assert.equal(buf.toString('hex'), '5b9ac8')
   })
 
   it('should handle exceptions and invalid inputs', () => {
     // should throw when invalid abi
-    assert.throws(() => (src as any).getKeys([], 3289), Error)
+    assert.throws(() => src.getKeys([], (<unknown>3289) as string), Error)
 
     // should detect invalid length hex string
-    assert.equal((src as any).isHexString('0x0', 2), false)
+    assert.equal(src.isHexString('0x0', 2), false)
   })
 })
diff --git a/tsconfig.json b/tsconfig.json
index ddbd8a97..e80502d7 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,4 +1,10 @@
 {
   "extends": "@ethereumjs/config-tsc",
+  "compilerOptions": {
+    "baseUrl": ".",
+    "paths": {
+      "*": ["src/@types/*"]
+    }
+  },
   "include": ["src/**/*.ts", "test/**/*.ts"]
 }
diff --git a/tsconfig.prod.json b/tsconfig.prod.json
index 184d95b5..f93323e1 100644
--- a/tsconfig.prod.json
+++ b/tsconfig.prod.json
@@ -1,7 +1,6 @@
 {
-  "extends": "@ethereumjs/config-tsc",
+  "extends": "./tsconfig.json",
   "compilerOptions": {
     "outDir": "./dist"
-  },
-  "include": ["src/**/*.ts"]
+  }
 }