diff --git a/shared/modules/buffer-utils.test.js b/shared/modules/buffer-utils.test.js
index 2f5290cca..f3daa9e17 100644
--- a/shared/modules/buffer-utils.test.js
+++ b/shared/modules/buffer-utils.test.js
@@ -1,4 +1,3 @@
-import { strict as assert } from 'assert';
 import BN from 'bn.js';
 import { toBuffer } from './buffer-utils';
 
@@ -6,64 +5,64 @@ describe('buffer utils', function () {
   describe('toBuffer', function () {
     it('should work with prefixed hex strings', function () {
       const result = toBuffer('0xe');
-      assert.equal(result.length, 1);
+      expect(result).toHaveLength(1);
     });
 
     it('should work with non prefixed hex strings', function () {
       const result = toBuffer('e');
-      assert.equal(result.length, 1);
+      expect(result).toHaveLength(1);
     });
 
     it('should work with weirdly 0x prefixed non-hex strings', function () {
       const result = toBuffer('0xtest');
-      assert.equal(result.length, 6);
+      expect(result).toHaveLength(6);
     });
 
     it('should work with regular strings', function () {
       const result = toBuffer('test');
-      assert.equal(result.length, 4);
+      expect(result).toHaveLength(4);
     });
 
     it('should work with BN', function () {
       const result = toBuffer(new BN(100));
-      assert.equal(result.length, 1);
+      expect(result).toHaveLength(1);
     });
 
     it('should work with Buffer', function () {
       const result = toBuffer(Buffer.from('test'));
-      assert.equal(result.length, 4);
+      expect(result).toHaveLength(4);
     });
 
     it('should work with a number', function () {
       const result = toBuffer(100);
-      assert.equal(result.length, 1);
+      expect(result).toHaveLength(1);
     });
 
     it('should work with null or undefined', function () {
       const result = toBuffer(null);
       const result2 = toBuffer(undefined);
-      assert.equal(result.length, 0);
-      assert.equal(result2.length, 0);
+      expect(result).toHaveLength(0);
+      expect(result2).toHaveLength(0);
     });
 
     it('should work with UInt8Array', function () {
       const uint8 = new Uint8Array(2);
       const result = toBuffer(uint8);
-      assert.equal(result.length, 2);
+      expect(result).toHaveLength(2);
     });
 
     it('should work with objects that have a toBuffer property', function () {
       const result = toBuffer({
         toBuffer: () => Buffer.from('hi'),
       });
-      assert.equal(result.length, 2);
+      expect(result).toHaveLength(2);
     });
 
     it('should work with objects that have a toArray property', function () {
       const result = toBuffer({
         toArray: () => ['hi'],
       });
-      assert.equal(result.length, 1);
+      expect(result).toHaveLength(1);
     });
   });
 });
diff --git a/shared/modules/fetch-with-timeout.test.js b/shared/modules/fetch-with-timeout.test.js
index 2061c2b92..a7400e617 100644
--- a/shared/modules/fetch-with-timeout.test.js
+++ b/shared/modules/fetch-with-timeout.test.js
@@ -1,6 +1,4 @@
-import { strict as assert } from 'assert';
 import nock from 'nock';
-
 import { MILLISECOND, SECOND } from '../constants/time';
 import getFetchWithTimeout from './fetch-with-timeout';
 
@@ -12,7 +10,7 @@ describe('getFetchWithTimeout', function () {
     const response = await (
       await fetchWithTimeout('https://api.infura.io/money')
     ).json();
-    assert.deepEqual(response, {
+    expect(response).toStrictEqual({
       hodl: false,
     });
   });
@@ -25,14 +23,14 @@ describe('getFetchWithTimeout', function () {
 
     const fetchWithTimeout = getFetchWithTimeout(MILLISECOND * 123);
 
-    try {
+    const fetchWithTimeoutThrowsError = async () => {
       await fetchWithTimeout('https://api.infura.io/moon').then((r) =>
         r.json(),
       );
-      assert.fail('Request should throw');
-    } catch (e) {
-      assert.ok(e);
-    }
+      throw new Error('Request should throw');
+    };
+
+    await expect(fetchWithTimeoutThrowsError()).rejects.toThrow('Aborted');
   });
 
   it('should abort the request when the custom timeout is hit', async function () {
@@ -43,20 +41,28 @@ describe('getFetchWithTimeout', function () {
 
     const fetchWithTimeout = getFetchWithTimeout(MILLISECOND * 123);
 
-    try {
+    const fetchWithTimeoutThrowsError = async () => {
       await fetchWithTimeout('https://api.infura.io/moon').then((r) =>
         r.json(),
       );
-      assert.fail('Request should be aborted');
-    } catch (e) {
-      assert.deepEqual(e.message, 'Aborted');
-    }
+      throw new Error('Request should be aborted');
+    };
+
+    await expect(fetchWithTimeoutThrowsError()).rejects.toThrow('Aborted');
   });
 
   it('throws on invalid timeout', async function () {
-    assert.throws(() => getFetchWithTimeout(), 'should throw');
-    assert.throws(() => getFetchWithTimeout(-1), 'should throw');
-    assert.throws(() => getFetchWithTimeout({}), 'should throw');
-    assert.throws(() => getFetchWithTimeout(true), 'should throw');
+    expect(() => getFetchWithTimeout()).toThrow(
+      'Must specify positive integer timeout.',
+    );
+    expect(() => getFetchWithTimeout(-1)).toThrow(
+      'Must specify positive integer timeout.',
+    );
+    expect(() => getFetchWithTimeout({})).toThrow(
+      'Must specify positive integer timeout.',
+    );
+    expect(() => getFetchWithTimeout(true)).toThrow(
+      'Must specify positive integer timeout.',
+    );
   });
 });
diff --git a/shared/modules/hexstring-utils.test.js b/shared/modules/hexstring-utils.test.js
index 3d292451e..bf2d80116 100644
--- a/shared/modules/hexstring-utils.test.js
+++ b/shared/modules/hexstring-utils.test.js
@@ -1,4 +1,3 @@
-import { strict as assert } from 'assert';
 import { toChecksumAddress } from 'ethereumjs-util';
 import { isValidHexAddress } from './hexstring-utils';
 
@@ -7,51 +6,51 @@ describe('hexstring utils', function () {
     it('should allow 40-char non-prefixed hex', function () {
       const address = 'fdea65c8e26263f6d9a1b5de9555d2931a33b825';
       const result = isValidHexAddress(address);
-      assert.equal(result, true);
+      expect(result).toBe(true);
     });
 
     it('should allow 42-char prefixed hex', function () {
       const address = '0xfdea65c8e26263f6d9a1b5de9555d2931a33b825';
       const result = isValidHexAddress(address);
-      assert.equal(result, true);
+      expect(result).toBe(true);
     });
 
     it('should NOT allow 40-char non-prefixed hex when allowNonPrefixed is false', function () {
       const address = 'fdea65c8e26263f6d9a1b5de9555d2931a33b825';
       const result = isValidHexAddress(address, { allowNonPrefixed: false });
-      assert.equal(result, false);
+      expect(result).toBe(false);
     });
 
     it('should NOT allow any length of non hex-prefixed string', function () {
       const address = 'fdea65c8e26263f6d9a1b5de9555d2931a33b85';
       const result = isValidHexAddress(address);
-      assert.equal(result, false);
+      expect(result).toBe(false);
     });
 
     it('should NOT allow less than 42 character hex-prefixed string', function () {
       const address = '0xfdea65ce26263f6d9a1b5de9555d2931a33b85';
       const result = isValidHexAddress(address);
-      assert.equal(result, false);
+      expect(result).toBe(false);
     });
 
     it('should recognize correct capitalized checksum', function () {
       const address = '0xFDEa65C8e26263F6d9A1B5de9555D2931A33b825';
       const result = isValidHexAddress(address, { mixedCaseUseChecksum: true });
-      assert.equal(result, true);
+      expect(result).toBe(true);
     });
 
     it('should recognize incorrect capitalized checksum', function () {
       const address = '0xFDea65C8e26263F6d9A1B5de9555D2931A33b825';
       const result = isValidHexAddress(address, { mixedCaseUseChecksum: true });
-      assert.equal(result, false);
+      expect(result).toBe(false);
     });
 
     it('should recognize this sample hashed address', function () {
       const address = '0x5Fda30Bb72B8Dfe20e48A00dFc108d0915BE9Bb0';
       const result = isValidHexAddress(address, { mixedCaseUseChecksum: true });
       const hashed = toChecksumAddress(address.toLowerCase());
-      assert.equal(hashed, address);
-      assert.equal(result, true);
+      expect(hashed).toBe(address);
+      expect(result).toBe(true);
     });
   });
 });