diff --git a/test/parallel/test-crypto.js b/test/parallel/test-crypto.js
index bf87900875..a325ee131c 100644
--- a/test/parallel/test-crypto.js
+++ b/test/parallel/test-crypto.js
@@ -1,34 +1,33 @@
 'use strict';
-var common = require('../common');
-var assert = require('assert');
-var util = require('util');
+const common = require('../common');
 
 if (!common.hasCrypto) {
   common.skip('missing crypto');
   return;
 }
-var crypto = require('crypto');
 
-crypto.DEFAULT_ENCODING = 'buffer';
+const assert = require('assert');
+const crypto = require('crypto');
+const fs = require('fs');
+const tls = require('tls');
 
-var fs = require('fs');
+crypto.DEFAULT_ENCODING = 'buffer';
 
 // Test Certificates
-var caPem = fs.readFileSync(common.fixturesDir + '/test_ca.pem', 'ascii');
-var certPem = fs.readFileSync(common.fixturesDir + '/test_cert.pem', 'ascii');
-var certPfx = fs.readFileSync(common.fixturesDir + '/test_cert.pfx');
-var keyPem = fs.readFileSync(common.fixturesDir + '/test_key.pem', 'ascii');
-var tls = require('tls');
+const caPem = fs.readFileSync(common.fixturesDir + '/test_ca.pem', 'ascii');
+const certPem = fs.readFileSync(common.fixturesDir + '/test_cert.pem', 'ascii');
+const certPfx = fs.readFileSync(common.fixturesDir + '/test_cert.pfx');
+const keyPem = fs.readFileSync(common.fixturesDir + '/test_key.pem', 'ascii');
 
 // 'this' safety
 // https://github.com/joyent/node/issues/6690
 assert.throws(function() {
-  var options = {key: keyPem, cert: certPem, ca: caPem};
-  var credentials = crypto.createCredentials(options);
-  var context = credentials.context;
-  var notcontext = { setOptions: context.setOptions, setKey: context.setKey };
-  crypto.createCredentials({ secureOptions: 1 }, notcontext);
-}, TypeError);
+  const options = {key: keyPem, cert: certPem, ca: caPem};
+  const credentials = tls.createSecureContext(options);
+  const context = credentials.context;
+  const notcontext = { setOptions: context.setOptions, setKey: context.setKey };
+  tls.createSecureContext({ secureOptions: 1 }, notcontext);
+}, /^TypeError: Illegal invocation$/);
 
 // PFX tests
 assert.doesNotThrow(function() {
@@ -37,55 +36,55 @@ assert.doesNotThrow(function() {
 
 assert.throws(function() {
   tls.createSecureContext({pfx: certPfx});
-}, 'mac verify failure');
+}, /^Error: mac verify failure$/);
 
 assert.throws(function() {
   tls.createSecureContext({pfx: certPfx, passphrase: 'test'});
-}, 'mac verify failure');
+}, /^Error: mac verify failure$/);
 
 assert.throws(function() {
   tls.createSecureContext({pfx: 'sample', passphrase: 'test'});
-}, 'not enough data');
+}, /^Error: not enough data$/);
 
 
 // update() should only take buffers / strings
 assert.throws(function() {
   crypto.createHash('sha1').update({foo: 'bar'});
-}, /buffer/);
+}, /^TypeError: Not a string or buffer$/);
 
 
 function assertSorted(list) {
   // Array#sort() modifies the list in place so make a copy.
-  var sorted = util._extend([], list).sort();
+  const sorted = list.slice().sort();
   assert.deepEqual(list, sorted);
 }
 
 // Assume that we have at least AES-128-CBC.
-assert.notEqual(0, crypto.getCiphers().length);
-assert.notEqual(-1, crypto.getCiphers().indexOf('aes-128-cbc'));
-assert.equal(-1, crypto.getCiphers().indexOf('AES-128-CBC'));
+assert.notStrictEqual(0, crypto.getCiphers().length);
+assert.notStrictEqual(-1, crypto.getCiphers().indexOf('aes-128-cbc'));
+assert.strictEqual(-1, crypto.getCiphers().indexOf('AES-128-CBC'));
 assertSorted(crypto.getCiphers());
 
 // Assume that we have at least AES256-SHA.
-assert.notEqual(0, tls.getCiphers().length);
-assert.notEqual(-1, tls.getCiphers().indexOf('aes256-sha'));
-assert.equal(-1, tls.getCiphers().indexOf('AES256-SHA'));
+assert.notStrictEqual(0, tls.getCiphers().length);
+assert.notStrictEqual(-1, tls.getCiphers().indexOf('aes256-sha'));
+assert.strictEqual(-1, tls.getCiphers().indexOf('AES256-SHA'));
 assertSorted(tls.getCiphers());
 
 // Assert that we have sha and sha1 but not SHA and SHA1.
-assert.notEqual(0, crypto.getHashes().length);
-assert.notEqual(-1, crypto.getHashes().indexOf('sha1'));
-assert.notEqual(-1, crypto.getHashes().indexOf('sha'));
-assert.equal(-1, crypto.getHashes().indexOf('SHA1'));
-assert.equal(-1, crypto.getHashes().indexOf('SHA'));
-assert.notEqual(-1, crypto.getHashes().indexOf('RSA-SHA1'));
-assert.equal(-1, crypto.getHashes().indexOf('rsa-sha1'));
+assert.notStrictEqual(0, crypto.getHashes().length);
+assert.notStrictEqual(-1, crypto.getHashes().indexOf('sha1'));
+assert.notStrictEqual(-1, crypto.getHashes().indexOf('sha'));
+assert.strictEqual(-1, crypto.getHashes().indexOf('SHA1'));
+assert.strictEqual(-1, crypto.getHashes().indexOf('SHA'));
+assert.notStrictEqual(-1, crypto.getHashes().indexOf('RSA-SHA1'));
+assert.strictEqual(-1, crypto.getHashes().indexOf('rsa-sha1'));
 assertSorted(crypto.getHashes());
 
 // Assume that we have at least secp384r1.
-assert.notEqual(0, crypto.getCurves().length);
-assert.notEqual(-1, crypto.getCurves().indexOf('secp384r1'));
-assert.equal(-1, crypto.getCurves().indexOf('SECP384R1'));
+assert.notStrictEqual(0, crypto.getCurves().length);
+assert.notStrictEqual(-1, crypto.getCurves().indexOf('secp384r1'));
+assert.strictEqual(-1, crypto.getCurves().indexOf('SECP384R1'));
 assertSorted(crypto.getCurves());
 
 // Regression tests for #5725: hex input that's not a power of two should
@@ -100,18 +99,18 @@ assert.throws(function() {
 
 assert.throws(function() {
   crypto.createHash('sha1').update('0', 'hex');
-}, /Bad input string/);
+}, /^TypeError: Bad input string$/);
 
 assert.throws(function() {
   crypto.createSign('RSA-SHA1').update('0', 'hex');
-}, /Bad input string/);
+}, /^TypeError: Bad input string$/);
 
 assert.throws(function() {
   crypto.createVerify('RSA-SHA1').update('0', 'hex');
-}, /Bad input string/);
+}, /^TypeError: Bad input string$/);
 
 assert.throws(function() {
-  var priv = [
+  const priv = [
     '-----BEGIN RSA PRIVATE KEY-----',
     'MIGrAgEAAiEA+3z+1QNF2/unumadiwEr+C5vfhezsb3hp4jAnCNRpPcCAwEAAQIgQNriSQK4',
     'EFwczDhMZp2dvbcz7OUUyt36z3S4usFPHSECEQD/41K7SujrstBfoCPzwC1xAhEA+5kt4BJy',
@@ -121,7 +120,7 @@ assert.throws(function() {
     ''
   ].join('\n');
   crypto.createSign('RSA-SHA256').update('test').sign(priv);
-}, /digest too big for rsa key/);
+}, /digest too big for rsa key$/);
 
 assert.throws(function() {
   // The correct header inside `test_bad_rsa_privkey.pem` should have been
@@ -133,7 +132,7 @@ assert.throws(function() {
   //   $ openssl pkcs8 -topk8 -inform PEM -outform PEM -in mykey.pem \
   //     -out private_key.pem -nocrypt;
   //   Then open private_key.pem and change its header and footer.
-  var sha1_privateKey = fs.readFileSync(common.fixturesDir +
+  const sha1_privateKey = fs.readFileSync(common.fixturesDir +
                                         '/test_bad_rsa_privkey.pem', 'ascii');
   // this would inject errors onto OpenSSL's error stack
   crypto.createSign('sha1').sign(sha1_privateKey);