diff --git a/karma.conf.js b/karma.conf.js
index d11df0c..f1a2b6a 100644
--- a/karma.conf.js
+++ b/karma.conf.js
@@ -9,10 +9,6 @@ module.exports = function(config) {
     karmaTypescriptConfig: {
       bundlerOptions: {
         entrypoints: /\.spec\.ts$/,
-        acornOptions: {
-          ecmaVersion: 8,
-        },
-        transforms: [require('karma-typescript-es6-transform')()],
       },
     },
     colors: true,
diff --git a/package.json b/package.json
index 55287be..97860eb 100644
--- a/package.json
+++ b/package.json
@@ -46,7 +46,7 @@
     "@web3-js/scrypt-shim": "^0.1.0",
     "aes-js": "^3.1.1",
     "bs58check": "^2.1.2",
-    "ethereumjs-util": "^6.0.0",
+    "ethereumjs-util": "^7.0.1",
     "hdkey": "^1.1.1",
     "randombytes": "^2.0.6",
     "utf8": "^3.0.0",
@@ -67,8 +67,7 @@
     "karma-chrome-launcher": "^2.0.0",
     "karma-firefox-launcher": "^1.0.0",
     "karma-mocha": "^2.0.0",
-    "karma-typescript": "^4.1.1",
-    "karma-typescript-es6-transform": "^5.0.2",
+    "karma-typescript": "^5.0.2",
     "lodash.zip": "^4.2.0",
     "mocha": "^7.1.2",
     "nyc": "^15.0.1",
diff --git a/src/index.ts b/src/index.ts
index 25c83d2..55be616 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -255,7 +255,7 @@ export default class Wallet {
     if (icapDirect) {
       const max = new ethUtil.BN('088f924eeceeda7fe92e1f5b0fffffffffffffff', 16)
       while (true) {
-        const privateKey = randomBytes(32)
+        const privateKey = randomBytes(32) as Buffer
         if (new ethUtil.BN(ethUtil.privateToAddress(privateKey)).lte(max)) {
           return new Wallet(privateKey)
         }
@@ -274,7 +274,7 @@ export default class Wallet {
     }
 
     while (true) {
-      const privateKey = randomBytes(32)
+      const privateKey = randomBytes(32) as Buffer
       const address = ethUtil.privateToAddress(privateKey)
 
       if (pattern.test(address.toString('hex'))) {
@@ -352,7 +352,7 @@ export default class Wallet {
       kdfparams.R,
       kdfparams.P,
       kdfparams.DkLen,
-    )
+    ) as Buffer
 
     const ciphertext = Buffer.from(json.Crypto.CipherText, 'hex')
     const mac = ethUtil.keccak256(Buffer.concat([derivedKey.slice(16, 32), ciphertext]))
@@ -399,7 +399,7 @@ export default class Wallet {
         kdfparams.r,
         kdfparams.p,
         kdfparams.dklen,
-      )
+      ) as Buffer
     } else if (json.crypto.kdf === 'pbkdf2') {
       kdfparams = json.crypto.kdfparams
 
@@ -572,7 +572,7 @@ export default class Wallet {
           kdfParams.r,
           kdfParams.p,
           kdfParams.dklen,
-        )
+        ) as Buffer
         break
       default:
         throw new Error('Unsupported kdf')
diff --git a/src/thirdparty.ts b/src/thirdparty.ts
index 5afb1fe..e9c8509 100644
--- a/src/thirdparty.ts
+++ b/src/thirdparty.ts
@@ -1,5 +1,5 @@
 import * as crypto from 'crypto'
-import * as ethUtil from 'ethereumjs-util'
+import { keccak256, sha256, toBuffer } from 'ethereumjs-util'
 
 import Wallet from './index'
 
@@ -167,7 +167,7 @@ export function fromEtherWallet(input: string | EtherWalletOptions, password: st
  * Third Party API: Import a brain wallet used by Ether.Camp
  */
 export function fromEtherCamp(passphrase: string): Wallet {
-  return new Wallet(ethUtil.keccak256(Buffer.from(passphrase)))
+  return new Wallet(keccak256(Buffer.from(passphrase)))
 }
 
 /**
@@ -210,13 +210,13 @@ export function fromKryptoKit(entropy: string, password: string): Wallet {
 
   let privateKey: Buffer
   if (type === 'd') {
-    privateKey = ethUtil.sha256(entropy)
+    privateKey = sha256(toBuffer(entropy))
   } else if (type === 'q') {
     if (typeof password !== 'string') {
       throw new Error('Password required')
     }
 
-    const encryptedSeed = ethUtil.sha256(Buffer.from(entropy.slice(0, 30)))
+    const encryptedSeed = sha256(Buffer.from(entropy.slice(0, 30)))
     const checksum = entropy.slice(30, 46)
 
     const salt = kryptoKitBrokenScryptSeed(encryptedSeed)
@@ -244,8 +244,7 @@ export function fromKryptoKit(entropy: string, password: string): Wallet {
     if (checksum.length > 0) {
       if (
         checksum !==
-        ethUtil
-          .sha256(ethUtil.sha256(privateKey))
+        sha256(sha256(privateKey))
           .slice(0, 8)
           .toString('hex')
       ) {
diff --git a/test/index.spec.ts b/test/index.spec.ts
index abd1b85..c5328b2 100644
--- a/test/index.spec.ts
+++ b/test/index.spec.ts
@@ -1,6 +1,6 @@
 /* tslint:disable no-invalid-this */
 import * as assert from 'assert'
-import * as ethUtil from 'ethereumjs-util'
+import { BN } from 'ethereumjs-util'
 import { Wallet as ethersWallet } from 'ethers'
 
 const zip = require('lodash.zip')
@@ -35,7 +35,7 @@ describe('.getPrivateKey()', function() {
   it('should fail', function() {
     assert.throws(function() {
       Wallet.fromPrivateKey(Buffer.from('001122', 'hex'))
-    }, /^Error: Private key does not satisfy the curve requirements \(ie. it is invalid\)$/)
+    }, /^Error: Expected private key to be an Uint8Array with length 32$/)
   })
 })
 
@@ -160,10 +160,10 @@ describe('.generate()', function() {
     assert.strictEqual(Wallet.generate().getPrivateKey().length, 32)
   })
   it('should generate an account compatible with ICAP Direct', function() {
-    const max = new ethUtil.BN('088f924eeceeda7fe92e1f5b0fffffffffffffff', 16)
+    const max = new BN('088f924eeceeda7fe92e1f5b0fffffffffffffff', 16)
     const wallet = Wallet.generate(true)
     assert.strictEqual(wallet.getPrivateKey().length, 32)
-    assert.strictEqual(new ethUtil.BN(wallet.getAddress()).lte(max), true)
+    assert.strictEqual(new BN(wallet.getAddress()).lte(max), true)
   })
 })