diff --git a/app/scripts/account-import-strategies/account-import-strategies.test.js b/app/scripts/account-import-strategies/account-import-strategies.test.js
index e29561639..7886f1717 100644
--- a/app/scripts/account-import-strategies/account-import-strategies.test.js
+++ b/app/scripts/account-import-strategies/account-import-strategies.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import { stripHexPrefix } from 'ethereumjs-util';
 import accountImporter from '.';
 
diff --git a/app/scripts/controllers/cached-balances.test.js b/app/scripts/controllers/cached-balances.test.js
index 94e86b41a..5ef473110 100644
--- a/app/scripts/controllers/cached-balances.test.js
+++ b/app/scripts/controllers/cached-balances.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import sinon from 'sinon';
 import { KOVAN_CHAIN_ID } from '../../../shared/constants/network';
 import CachedBalancesController from './cached-balances';
diff --git a/app/scripts/controllers/detect-tokens.test.js b/app/scripts/controllers/detect-tokens.test.js
index c472c7977..3b5eddd24 100644
--- a/app/scripts/controllers/detect-tokens.test.js
+++ b/app/scripts/controllers/detect-tokens.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import sinon from 'sinon';
 import { ObservableStore } from '@metamask/obs-store';
 import contracts from '@metamask/contract-metadata';
diff --git a/app/scripts/controllers/ens/index.test.js b/app/scripts/controllers/ens/index.test.js
index 24197dbd7..c94f73a5d 100644
--- a/app/scripts/controllers/ens/index.test.js
+++ b/app/scripts/controllers/ens/index.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import sinon from 'sinon';
 import EnsController from '.';
 
diff --git a/app/scripts/controllers/incoming-transactions.test.js b/app/scripts/controllers/incoming-transactions.test.js
index 74aaad78c..347fa7952 100644
--- a/app/scripts/controllers/incoming-transactions.test.js
+++ b/app/scripts/controllers/incoming-transactions.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import sinon from 'sinon';
 import proxyquire from 'proxyquire';
 import nock from 'nock';
diff --git a/app/scripts/controllers/network/network.js b/app/scripts/controllers/network/network.js
index cd0fc0bce..a308a7d4b 100644
--- a/app/scripts/controllers/network/network.js
+++ b/app/scripts/controllers/network/network.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import EventEmitter from 'events';
 import { ComposedStore, ObservableStore } from '@metamask/obs-store';
 import { JsonRpcEngine } from 'json-rpc-engine';
diff --git a/app/scripts/controllers/network/pending-middleware.test.js b/app/scripts/controllers/network/pending-middleware.test.js
index 1ce327b22..49e60aaa4 100644
--- a/app/scripts/controllers/network/pending-middleware.test.js
+++ b/app/scripts/controllers/network/pending-middleware.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import { txMetaStub } from '../../../../test/stub/tx-meta-stub';
 import {
   createPendingNonceMiddleware,
diff --git a/app/scripts/controllers/preferences.test.js b/app/scripts/controllers/preferences.test.js
index 1c765a92b..4141f0f5f 100644
--- a/app/scripts/controllers/preferences.test.js
+++ b/app/scripts/controllers/preferences.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import sinon from 'sinon';
 import {
   MAINNET_CHAIN_ID,
diff --git a/app/scripts/controllers/swaps.test.js b/app/scripts/controllers/swaps.test.js
index 4e85aa393..0fb1d80ac 100644
--- a/app/scripts/controllers/swaps.test.js
+++ b/app/scripts/controllers/swaps.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import sinon from 'sinon';
 
 import { ethers } from 'ethers';
@@ -645,7 +645,7 @@ describe('SwapsController', function () {
           topAggId,
           resultQuotes,
         ] = await swapsController._findTopQuoteAndCalculateSavings(testInput);
-        assert.equal(topAggId, [TEST_AGG_ID_2]);
+        assert.equal(topAggId, TEST_AGG_ID_2);
         assert.deepStrictEqual(resultQuotes, expectedResultQuotes);
       });
     });
diff --git a/app/scripts/controllers/token-rates-controller.test.js b/app/scripts/controllers/token-rates-controller.test.js
index fc5d3af52..444e53977 100644
--- a/app/scripts/controllers/token-rates-controller.test.js
+++ b/app/scripts/controllers/token-rates-controller.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import sinon from 'sinon';
 import { ObservableStore } from '@metamask/obs-store';
 import TokenRatesController from './token-rates';
diff --git a/app/scripts/lib/ComposableObservableStore.test.js b/app/scripts/lib/ComposableObservableStore.test.js
index a079984c1..2ae9b508f 100644
--- a/app/scripts/lib/ComposableObservableStore.test.js
+++ b/app/scripts/lib/ComposableObservableStore.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import { ObservableStore } from '@metamask/obs-store';
 import ComposableObservableStore from './ComposableObservableStore';
 
diff --git a/app/scripts/lib/buy-eth-url.test.js b/app/scripts/lib/buy-eth-url.test.js
index 17ba3d64a..01837c8ef 100644
--- a/app/scripts/lib/buy-eth-url.test.js
+++ b/app/scripts/lib/buy-eth-url.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import {
   KOVAN_CHAIN_ID,
   MAINNET_CHAIN_ID,
diff --git a/app/scripts/lib/cleanErrorStack.test.js b/app/scripts/lib/cleanErrorStack.test.js
index 9f01e8252..b87152f21 100644
--- a/app/scripts/lib/cleanErrorStack.test.js
+++ b/app/scripts/lib/cleanErrorStack.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import cleanErrorStack from './cleanErrorStack';
 
 describe('Clean Error Stack', function () {
@@ -14,7 +14,7 @@ describe('Clean Error Stack', function () {
   });
 
   it('tests error with message', function () {
-    assert.equal(cleanErrorStack(testError), 'Error: Test Message');
+    assert.equal(cleanErrorStack(testError).toString(), 'Error: Test Message');
   });
 
   it('tests error with undefined name', function () {
@@ -29,6 +29,6 @@ describe('Clean Error Stack', function () {
   });
 
   it('tests error with blank message', function () {
-    assert.equal(cleanErrorStack(blankMsgError), 'Error');
+    assert.equal(cleanErrorStack(blankMsgError).toString(), 'Error');
   });
 });
diff --git a/app/scripts/lib/createMetaRPCHandler.test.js b/app/scripts/lib/createMetaRPCHandler.test.js
index e37985105..638b018b6 100644
--- a/app/scripts/lib/createMetaRPCHandler.test.js
+++ b/app/scripts/lib/createMetaRPCHandler.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import { obj as createThoughStream } from 'through2';
 import createMetaRPCHandler from './createMetaRPCHandler';
 
diff --git a/app/scripts/lib/message-manager.test.js b/app/scripts/lib/message-manager.test.js
index 947cb2688..39183fb7a 100644
--- a/app/scripts/lib/message-manager.test.js
+++ b/app/scripts/lib/message-manager.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import { TRANSACTION_STATUSES } from '../../../shared/constants/transaction';
 import MessageManager from './message-manager';
 
diff --git a/app/scripts/lib/metaRPCClientFactory.test.js b/app/scripts/lib/metaRPCClientFactory.test.js
index d270a4e1a..624113c1a 100644
--- a/app/scripts/lib/metaRPCClientFactory.test.js
+++ b/app/scripts/lib/metaRPCClientFactory.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import { obj as createThoughStream } from 'through2';
 import metaRPCClientFactory from './metaRPCClientFactory';
 
diff --git a/app/scripts/lib/migrator/index.test.js b/app/scripts/lib/migrator/index.test.js
index 0fbb3e8a9..cdaac9e82 100644
--- a/app/scripts/lib/migrator/index.test.js
+++ b/app/scripts/lib/migrator/index.test.js
@@ -1,5 +1,5 @@
 import fs from 'fs';
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import { cloneDeep } from 'lodash';
 import liveMigrations from '../../migrations';
 import data from '../../first-time-state';
diff --git a/app/scripts/lib/nodeify.test.js b/app/scripts/lib/nodeify.test.js
index 4f2c2a2eb..accfc48e8 100644
--- a/app/scripts/lib/nodeify.test.js
+++ b/app/scripts/lib/nodeify.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import nodeify from './nodeify';
 
 describe('nodeify', function () {
diff --git a/app/scripts/lib/personal-message-manager.test.js b/app/scripts/lib/personal-message-manager.test.js
index c3ce3f615..de241fff0 100644
--- a/app/scripts/lib/personal-message-manager.test.js
+++ b/app/scripts/lib/personal-message-manager.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import { TRANSACTION_STATUSES } from '../../../shared/constants/transaction';
 import PersonalMessageManager from './personal-message-manager';
 
diff --git a/app/scripts/lib/seed-phrase-verifier.test.js b/app/scripts/lib/seed-phrase-verifier.test.js
index d7ac0143f..1a6443935 100644
--- a/app/scripts/lib/seed-phrase-verifier.test.js
+++ b/app/scripts/lib/seed-phrase-verifier.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import { cloneDeep } from 'lodash';
 import KeyringController from 'eth-keyring-controller';
 import firstTimeState from '../first-time-state';
diff --git a/app/scripts/lib/typed-message-manager.js b/app/scripts/lib/typed-message-manager.js
index 28e7a2534..3da405cf1 100644
--- a/app/scripts/lib/typed-message-manager.js
+++ b/app/scripts/lib/typed-message-manager.js
@@ -1,5 +1,5 @@
 import EventEmitter from 'events';
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import { ObservableStore } from '@metamask/obs-store';
 import { ethErrors } from 'eth-rpc-errors';
 import { typedSignatureHash, TYPED_MESSAGE_SCHEMA } from 'eth-sig-util';
diff --git a/app/scripts/lib/typed-message-manager.test.js b/app/scripts/lib/typed-message-manager.test.js
index c994a586f..a9722211e 100644
--- a/app/scripts/lib/typed-message-manager.test.js
+++ b/app/scripts/lib/typed-message-manager.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import sinon from 'sinon';
 import { TRANSACTION_STATUSES } from '../../../shared/constants/transaction';
 import TypedMessageManager from './typed-message-manager';
diff --git a/app/scripts/lib/util.js b/app/scripts/lib/util.js
index 46e5b8641..126e5c4f6 100644
--- a/app/scripts/lib/util.js
+++ b/app/scripts/lib/util.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import extension from 'extensionizer';
 import { stripHexPrefix } from 'ethereumjs-util';
 import BN from 'bn.js';
diff --git a/app/scripts/metamask-controller.test.js b/app/scripts/metamask-controller.test.js
index f458f62b9..3d8cb57cf 100644
--- a/app/scripts/metamask-controller.test.js
+++ b/app/scripts/metamask-controller.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import sinon from 'sinon';
 import { cloneDeep } from 'lodash';
 import nock from 'nock';
@@ -493,8 +493,8 @@ describe('MetaMaskController', function () {
         );
       } catch (e) {
         assert.equal(
-          e,
-          'Error: MetamaskController:getKeyringForDevice - Unknown device',
+          e.message,
+          'MetamaskController:getKeyringForDevice - Unknown device',
         );
       }
     });
@@ -535,8 +535,8 @@ describe('MetaMaskController', function () {
         );
       } catch (e) {
         assert.equal(
-          e,
-          'Error: MetamaskController:getKeyringForDevice - Unknown device',
+          e.message,
+          'MetamaskController:getKeyringForDevice - Unknown device',
         );
       }
     });
@@ -554,8 +554,8 @@ describe('MetaMaskController', function () {
         await metamaskController.forgetDevice('Some random device name');
       } catch (e) {
         assert.equal(
-          e,
-          'Error: MetamaskController:getKeyringForDevice - Unknown device',
+          e.message,
+          'MetamaskController:getKeyringForDevice - Unknown device',
         );
       }
     });
diff --git a/app/scripts/migrations/021.test.js b/app/scripts/migrations/021.test.js
index 45c727e57..261d40f81 100644
--- a/app/scripts/migrations/021.test.js
+++ b/app/scripts/migrations/021.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import wallet2 from '../../../test/lib/migrations/002.json';
 import migration21 from './021';
 
diff --git a/app/scripts/migrations/022.test.js b/app/scripts/migrations/022.test.js
index a102bcb7e..425bfeb91 100644
--- a/app/scripts/migrations/022.test.js
+++ b/app/scripts/migrations/022.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import { TRANSACTION_STATUSES } from '../../../shared/constants/transaction';
 import migration22 from './022';
 
diff --git a/app/scripts/migrations/023.test.js b/app/scripts/migrations/023.test.js
index 0b40679b2..0ef74beb6 100644
--- a/app/scripts/migrations/023.test.js
+++ b/app/scripts/migrations/023.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import { TRANSACTION_STATUSES } from '../../../shared/constants/transaction';
 import migration23 from './023';
 
diff --git a/app/scripts/migrations/024.test.js b/app/scripts/migrations/024.test.js
index b2056193d..f87e45748 100644
--- a/app/scripts/migrations/024.test.js
+++ b/app/scripts/migrations/024.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import data from '../first-time-state';
 import { TRANSACTION_STATUSES } from '../../../shared/constants/transaction';
 import migration24 from './024';
diff --git a/app/scripts/migrations/025.test.js b/app/scripts/migrations/025.test.js
index 7d666c517..9e0ff846b 100644
--- a/app/scripts/migrations/025.test.js
+++ b/app/scripts/migrations/025.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import data from '../first-time-state';
 import { TRANSACTION_STATUSES } from '../../../shared/constants/transaction';
 import migration25 from './025';
diff --git a/app/scripts/migrations/026.test.js b/app/scripts/migrations/026.test.js
index 71245115b..ca4ac9a64 100644
--- a/app/scripts/migrations/026.test.js
+++ b/app/scripts/migrations/026.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import firstTimeState from '../first-time-state';
 import migration26 from './026';
 
diff --git a/app/scripts/migrations/027.test.js b/app/scripts/migrations/027.test.js
index 2687e17c2..29df2dfb0 100644
--- a/app/scripts/migrations/027.test.js
+++ b/app/scripts/migrations/027.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import firstTimeState from '../first-time-state';
 import { TRANSACTION_STATUSES } from '../../../shared/constants/transaction';
 import migration27 from './027';
diff --git a/app/scripts/migrations/028.test.js b/app/scripts/migrations/028.test.js
index 01381e754..5d755f50c 100644
--- a/app/scripts/migrations/028.test.js
+++ b/app/scripts/migrations/028.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import firstTimeState from '../first-time-state';
 import migration28 from './028';
 
diff --git a/app/scripts/migrations/029.test.js b/app/scripts/migrations/029.test.js
index 90d698fd7..53ce28695 100644
--- a/app/scripts/migrations/029.test.js
+++ b/app/scripts/migrations/029.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import { TRANSACTION_STATUSES } from '../../../shared/constants/transaction';
 import migration29 from './029';
 
diff --git a/app/scripts/migrations/030.test.js b/app/scripts/migrations/030.test.js
index 985aa02e1..f03f51231 100644
--- a/app/scripts/migrations/030.test.js
+++ b/app/scripts/migrations/030.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import migrationTemplate from './030';
 
 const storage = {
diff --git a/app/scripts/migrations/031.test.js b/app/scripts/migrations/031.test.js
index d7b6ee046..62216e85d 100644
--- a/app/scripts/migrations/031.test.js
+++ b/app/scripts/migrations/031.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import migration31 from './031';
 
 describe('migration #31', function () {
diff --git a/app/scripts/migrations/033.test.js b/app/scripts/migrations/033.test.js
index bb12e83d7..382622d39 100644
--- a/app/scripts/migrations/033.test.js
+++ b/app/scripts/migrations/033.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import migration33 from './033';
 
 describe('Migration to delete notice controller', function () {
diff --git a/app/scripts/migrations/034.test.js b/app/scripts/migrations/034.test.js
index bfb929997..7902b5f13 100644
--- a/app/scripts/migrations/034.test.js
+++ b/app/scripts/migrations/034.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import migration34 from './034';
 
 describe('migration #34', function () {
diff --git a/app/scripts/migrations/035.test.js b/app/scripts/migrations/035.test.js
index 385f12fb5..03454b2ea 100644
--- a/app/scripts/migrations/035.test.js
+++ b/app/scripts/migrations/035.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import migration35 from './035';
 
 describe('migration #35', function () {
diff --git a/app/scripts/migrations/036.test.js b/app/scripts/migrations/036.test.js
index 679080bf7..ecc44c557 100644
--- a/app/scripts/migrations/036.test.js
+++ b/app/scripts/migrations/036.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import migration36 from './036';
 
 describe('migration #36', function () {
diff --git a/app/scripts/migrations/037.test.js b/app/scripts/migrations/037.test.js
index 0c145bccf..688f66a9a 100644
--- a/app/scripts/migrations/037.test.js
+++ b/app/scripts/migrations/037.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import migration37 from './037';
 
 describe('migration #37', function () {
diff --git a/app/scripts/migrations/039.test.js b/app/scripts/migrations/039.test.js
index 55ba12982..3efbbf49d 100644
--- a/app/scripts/migrations/039.test.js
+++ b/app/scripts/migrations/039.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import migration39 from './039';
 
 describe('migration #39', function () {
diff --git a/app/scripts/migrations/040.test.js b/app/scripts/migrations/040.test.js
index f4d1de68e..ba10e4b75 100644
--- a/app/scripts/migrations/040.test.js
+++ b/app/scripts/migrations/040.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import migration40 from './040';
 
 describe('migration #40', function () {
diff --git a/app/scripts/migrations/041.test.js b/app/scripts/migrations/041.test.js
index 7c6e4c567..f1a06a151 100644
--- a/app/scripts/migrations/041.test.js
+++ b/app/scripts/migrations/041.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import migration41 from './041';
 
 describe('migration #41', function () {
diff --git a/app/scripts/migrations/042.test.js b/app/scripts/migrations/042.test.js
index 7cca8d2a7..8c1a46513 100644
--- a/app/scripts/migrations/042.test.js
+++ b/app/scripts/migrations/042.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import migration42 from './042';
 
 describe('migration #42', function () {
diff --git a/app/scripts/migrations/045.test.js b/app/scripts/migrations/045.test.js
index 907489195..de47bef32 100644
--- a/app/scripts/migrations/045.test.js
+++ b/app/scripts/migrations/045.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import migration45 from './045';
 
 describe('migration #45', function () {
diff --git a/app/scripts/migrations/049.test.js b/app/scripts/migrations/049.test.js
index 5242fab52..f3c89d66b 100644
--- a/app/scripts/migrations/049.test.js
+++ b/app/scripts/migrations/049.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import migration49 from './049';
 
 describe('migration #49', function () {
diff --git a/app/scripts/migrations/052.test.js b/app/scripts/migrations/052.test.js
index 8d9d13afb..3896d0a77 100644
--- a/app/scripts/migrations/052.test.js
+++ b/app/scripts/migrations/052.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import {
   GOERLI,
   GOERLI_CHAIN_ID,
diff --git a/app/scripts/migrations/056.test.js b/app/scripts/migrations/056.test.js
index e311d4aee..927997fbe 100644
--- a/app/scripts/migrations/056.test.js
+++ b/app/scripts/migrations/056.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import migration56 from './056';
 
 const BAD_TOKEN_DATA = { symbol: null, decimals: null };
diff --git a/app/scripts/migrations/migrations.test.js b/app/scripts/migrations/migrations.test.js
index a7c921323..82d15f501 100644
--- a/app/scripts/migrations/migrations.test.js
+++ b/app/scripts/migrations/migrations.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import wallet1 from '../../../test/lib/migrations/001.json';
 import vault4 from '../../../test/lib/migrations/004.json';
 import migration2 from './002';
@@ -52,7 +52,7 @@ describe('wallet1 is migrated successfully', function () {
         const fourthData = fourthResult.data;
         assert.equal(
           fourthData.config.provider.rpcTarget,
-          null,
+          undefined,
           'old rpcTarget should not exist.',
         );
         assert.equal(
@@ -65,15 +65,15 @@ describe('wallet1 is migrated successfully', function () {
       })
       .then((fifthResult) => {
         const fifthData = fifthResult.data;
-        assert.equal(fifthData.vault, null, 'old vault should not exist');
+        assert.equal(fifthData.vault, undefined, 'old vault should not exist');
         assert.equal(
           fifthData.walletNicknames,
-          null,
+          undefined,
           'old walletNicknames should not exist',
         );
         assert.equal(
           fifthData.config.selectedAccount,
-          null,
+          undefined,
           'old config.selectedAccount should not exist',
         );
         assert.equal(
@@ -102,7 +102,7 @@ describe('wallet1 is migrated successfully', function () {
       .then((sixthResult) => {
         assert.equal(
           sixthResult.data.KeyringController.selectedAccount,
-          null,
+          undefined,
           'old selectedAccount should not exist',
         );
         assert.equal(
@@ -117,12 +117,12 @@ describe('wallet1 is migrated successfully', function () {
       .then((seventhResult) => {
         assert.equal(
           seventhResult.data.transactions,
-          null,
+          undefined,
           'old transactions should not exist',
         );
         assert.equal(
           seventhResult.data.gasMultiplier,
-          null,
+          undefined,
           'old gasMultiplier should not exist',
         );
         assert.equal(
@@ -142,7 +142,7 @@ describe('wallet1 is migrated successfully', function () {
       .then((eighthResult) => {
         assert.equal(
           eighthResult.data.noticesList,
-          null,
+          undefined,
           'old noticesList should not exist',
         );
         assert.equal(
@@ -157,22 +157,22 @@ describe('wallet1 is migrated successfully', function () {
       .then((ninthResult) => {
         assert.equal(
           ninthResult.data.currentFiat,
-          null,
+          undefined,
           'old currentFiat should not exist',
         );
         assert.equal(
           ninthResult.data.fiatCurrency,
-          null,
+          undefined,
           'old fiatCurrency should not exist',
         );
         assert.equal(
           ninthResult.data.conversionRate,
-          null,
+          undefined,
           'old conversionRate should not exist',
         );
         assert.equal(
           ninthResult.data.conversionDate,
-          null,
+          undefined,
           'old conversionDate should not exist',
         );
 
@@ -198,7 +198,7 @@ describe('wallet1 is migrated successfully', function () {
       .then((tenthResult) => {
         assert.equal(
           tenthResult.data.shapeShiftTxList,
-          null,
+          undefined,
           'old shapeShiftTxList should not exist',
         );
         assert.equal(
@@ -211,12 +211,12 @@ describe('wallet1 is migrated successfully', function () {
       .then((eleventhResult) => {
         assert.equal(
           eleventhResult.data.isDisclaimerConfirmed,
-          null,
+          undefined,
           'isDisclaimerConfirmed should not exist',
         );
         assert.equal(
           eleventhResult.data.TOSHash,
-          null,
+          undefined,
           'TOSHash should not exist',
         );
 
diff --git a/app/scripts/migrations/template.test.js b/app/scripts/migrations/template.test.js
index 92a4e8937..5277b86ba 100644
--- a/app/scripts/migrations/template.test.js
+++ b/app/scripts/migrations/template.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import migrationTemplate from './template';
 
 const storage = {
diff --git a/shared/modules/fetch-with-timeout.test.js b/shared/modules/fetch-with-timeout.test.js
index a7b1daa1a..3b9ce1552 100644
--- a/shared/modules/fetch-with-timeout.test.js
+++ b/shared/modules/fetch-with-timeout.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import nock from 'nock';
 
 import getFetchWithTimeout from './fetch-with-timeout';
diff --git a/shared/modules/tests/transaction.utils.test.js b/shared/modules/tests/transaction.utils.test.js
index 2aac76828..0da399f34 100644
--- a/shared/modules/tests/transaction.utils.test.js
+++ b/shared/modules/tests/transaction.utils.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import {
   MAINNET_CHAIN_ID,
   MAINNET_NETWORK_ID,
diff --git a/test/e2e/metamask-ui.spec.js b/test/e2e/metamask-ui.spec.js
index 2e88fc278..92390f33f 100644
--- a/test/e2e/metamask-ui.spec.js
+++ b/test/e2e/metamask-ui.spec.js
@@ -1,4 +1,4 @@
-const assert = require('assert');
+const { strict: assert } = require('assert');
 
 const enLocaleMessages = require('../../app/_locales/en/messages.json');
 const { tinyDelayMs, regularDelayMs, largeDelayMs } = require('./helpers');
diff --git a/test/unit-global/balance-formatter.test.js b/test/unit-global/balance-formatter.test.js
index d96668e3b..36c246bfd 100644
--- a/test/unit-global/balance-formatter.test.js
+++ b/test/unit-global/balance-formatter.test.js
@@ -1,4 +1,4 @@
-import assert from 'assert';
+import { strict as assert } from 'assert';
 import currencyFormatter from 'currency-formatter';
 import availableCurrencies from '../../ui/helpers/constants/available-conversions.json';
 
diff --git a/test/unit-global/frozenPromise.test.js b/test/unit-global/frozenPromise.test.js
index de2409792..f96af0d2a 100644
--- a/test/unit-global/frozenPromise.test.js
+++ b/test/unit-global/frozenPromise.test.js
@@ -2,7 +2,7 @@
 import './globalPatch';
 import 'ses/lockdown';
 import '../../app/scripts/runLockdown';
-import assert from 'assert'; /* eslint-disable-line import/first,import/order */
+import { strict as assert } from 'assert'; /* eslint-disable-line import/first,import/order */
 
 describe('Promise global is immutable', function () {
   it('throws when reassinging promise (syntax 1)', function () {