diff --git a/test/parallel/test-http-client-req-error-dont-double-fire.js b/test/parallel/test-http-client-req-error-dont-double-fire.js
index 996540fc96c72e..d2c526eab69c6c 100644
--- a/test/parallel/test-http-client-req-error-dont-double-fire.js
+++ b/test/parallel/test-http-client-req-error-dont-double-fire.js
@@ -1,11 +1,21 @@
 'use strict';
+
+// This tests that the error emitted on the socket does
+// not get fired again when the 'error' event handler throws
+// an error.
+
 const assert = require('assert');
 const http = require('http');
 const common = require('../common');
+const { addresses } = require('../common/internet');
+const { errorLookupMock } = require('../common/dns');
+
+const host = addresses.INVALID_HOST;
 
-// Invalid hostname as per https://tools.ietf.org/html/rfc2606#section-2
-const host = 'this.hostname.is.invalid';
-const req = http.get({ host });
+const req = http.get({
+  host,
+  lookup: common.mustCall(errorLookupMock())
+});
 const err = new Error('mock unexpected code error');
 req.on('error', common.mustCall(() => {
   throw err;
diff --git a/test/parallel/test-net-better-error-messages-port-hostname.js b/test/parallel/test-net-better-error-messages-port-hostname.js
index 818ea4bfff41f6..1a8aa770b44a22 100644
--- a/test/parallel/test-net-better-error-messages-port-hostname.js
+++ b/test/parallel/test-net-better-error-messages-port-hostname.js
@@ -1,21 +1,30 @@
 'use strict';
+
+// This tests that the error thrown from net.createConnection
+// comes with host and port properties.
+// See https://github.com/nodejs/node-v0.x-archive/issues/7005
+
 const common = require('../common');
 const net = require('net');
 const assert = require('assert');
 
+const { addresses } = require('../common/internet');
+const {
+  errorLookupMock,
+  mockedErrorCode
+} = require('../common/dns');
+
 // Using port 0 as hostname used is already invalid.
-const c = net.createConnection(0, 'this.hostname.is.invalid');
+const c = net.createConnection({
+  port: 0,
+  host: addresses.INVALID_HOST,
+  lookup: common.mustCall(errorLookupMock())
+});
 
 c.on('connect', common.mustNotCall());
 
 c.on('error', common.mustCall(function(e) {
-  // If Name Service Switch is available on the operating system then it
-  // might be configured differently (/etc/nsswitch.conf).
-  // If the system is configured with no dns the error code will be EAI_AGAIN,
-  // but if there are more services after the dns entry, for example some
-  // linux distributions ship a myhostname service by default which would
-  // still produce the ENOTFOUND error.
-  assert.ok(e.code === 'ENOTFOUND' || e.code === 'EAI_AGAIN');
+  assert.strictEqual(e.code, mockedErrorCode);
   assert.strictEqual(e.port, 0);
-  assert.strictEqual(e.hostname, 'this.hostname.is.invalid');
+  assert.strictEqual(e.hostname, addresses.INVALID_HOST);
 }));
diff --git a/test/parallel/test-net-connect-immediate-finish.js b/test/parallel/test-net-connect-immediate-finish.js
index e2e5e1c6715b9a..9adf8c31128b00 100644
--- a/test/parallel/test-net-connect-immediate-finish.js
+++ b/test/parallel/test-net-connect-immediate-finish.js
@@ -20,28 +20,35 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
+
+// This tests that if the socket is still in the 'connecting' state
+// when the user calls socket.end() ('finish'), the socket would emit
+// 'connect' and defer the handling until the 'connect' event is handled.
+
 const common = require('../common');
 const assert = require('assert');
 const net = require('net');
 
+const { addresses } = require('../common/internet');
+const {
+  errorLookupMock,
+  mockedErrorCode,
+  mockedSysCall
+} = require('../common/dns');
+
 const client = net.connect({
-  host: 'this.hostname.is.invalid',
-  port: common.PORT
+  host: addresses.INVALID_HOST,
+  port: common.PORT,
+  lookup: common.mustCall(errorLookupMock())
 });
 
 client.once('error', common.mustCall((err) => {
   assert(err);
   assert.strictEqual(err.code, err.errno);
-  // If Name Service Switch is available on the operating system then it
-  // might be configured differently (/etc/nsswitch.conf).
-  // If the system is configured with no dns the error code will be EAI_AGAIN,
-  // but if there are more services after the dns entry, for example some
-  // linux distributions ship a myhostname service by default which would
-  // still produce the ENOTFOUND error.
-  assert.ok(err.code === 'ENOTFOUND' || err.code === 'EAI_AGAIN');
+  assert.strictEqual(err.code, mockedErrorCode);
   assert.strictEqual(err.host, err.hostname);
-  assert.strictEqual(err.host, 'this.hostname.is.invalid');
-  assert.strictEqual(err.syscall, 'getaddrinfo');
+  assert.strictEqual(err.host, addresses.INVALID_HOST);
+  assert.strictEqual(err.syscall, mockedSysCall);
 }));
 
 client.end();