diff --git a/test/parallel/test-child-process-spawnsync-env.js b/test/parallel/test-child-process-spawnsync-env.js
index bc7c5aa3dd6c14..3147bdd91c0a17 100644
--- a/test/parallel/test-child-process-spawnsync-env.js
+++ b/test/parallel/test-child-process-spawnsync-env.js
@@ -7,9 +7,12 @@ if (process.argv[2] === 'child') {
   console.log(process.env.foo);
 } else {
   var expected = 'bar';
-  var child = cp.spawnSync(process.execPath, [__filename, 'child'], {
-    env: {foo: expected}
-  });
+  var opt = {
+    env: process.env
+  };
+  opt.env.foo = expected;
+
+  var child = cp.spawnSync(process.execPath, [__filename, 'child'], opt);
 
   assert.equal(child.stdout.toString().trim(), expected);
 }
diff --git a/test/parallel/test-fs-readfile-error.js b/test/parallel/test-fs-readfile-error.js
index c198d7d0ebc638..2256ea6c6de200 100644
--- a/test/parallel/test-fs-readfile-error.js
+++ b/test/parallel/test-fs-readfile-error.js
@@ -25,13 +25,15 @@ function test(env, cb) {
   });
 }
 
-test({ NODE_DEBUG: '' }, function(data) {
+process.env.NODE_DEBUG = '';
+test(process.env, function(data) {
   assert(/EISDIR/.test(data));
   assert(!/test-fs-readfile-error/.test(data));
   callbacks++;
 });
 
-test({ NODE_DEBUG: 'fs' }, function(data) {
+process.env.NODE_DEBUG = 'fs';
+test(process.env, function(data) {
   assert(/EISDIR/.test(data));
   assert(/test-fs-readfile-error/.test(data));
   callbacks++;
diff --git a/test/sequential/test-net-GH-5504.js b/test/sequential/test-net-GH-5504.js
index 0478de55d62592..6cfa2c10500983 100644
--- a/test/sequential/test-net-GH-5504.js
+++ b/test/sequential/test-net-GH-5504.js
@@ -54,11 +54,9 @@ function parent() {
   var clientExited = false;
   var serverListened = false;
   var opt = {
-    env: {
-      NODE_DEBUG: 'net',
-      NODE_COMMON_PORT: process.env.NODE_COMMON_PORT,
-    }
+    env: process.env
   };
+  opt.env.NODE_DEBUG = 'net';
 
   process.on('exit', function() {
     assert(serverExited);
diff --git a/test/sequential/test-stdin-script-child.js b/test/sequential/test-stdin-script-child.js
index 8590df02d8efe9..426bada309461b 100644
--- a/test/sequential/test-stdin-script-child.js
+++ b/test/sequential/test-stdin-script-child.js
@@ -3,11 +3,12 @@ var common = require('../common');
 var assert = require('assert');
 
 var spawn = require('child_process').spawn;
-var child = spawn(process.execPath, [], {
-  env: {
-    NODE_DEBUG: process.argv[2]
-  }
-});
+var opt = {
+  env: process.env
+};
+
+opt.env.NODE_DEBUG = process.argv[2];
+var child = spawn(process.execPath, [], opt);
 var wanted = child.pid + '\n';
 var found = '';
 
diff --git a/test/sequential/test-util-debug.js b/test/sequential/test-util-debug.js
index 834c21ec0e50b4..9ab2cdd8d362d4 100644
--- a/test/sequential/test-util-debug.js
+++ b/test/sequential/test-util-debug.js
@@ -26,14 +26,17 @@ function test(environ, shouldWrite) {
   var didTest = false;
 
   var spawn = require('child_process').spawn;
-  var child = spawn(process.execPath, [__filename, 'child'], {
-    // Lttng requires the HOME env variable or it prints to stderr,
-    // This is not really ideal, as it breaks this test, so the HOME
-    // env variable is passed to the child to make the test pass.
-    // this is fixed in the next version of lttng (2.7+), so we can
-    // remove it at sometime in the future.
-    env: { NODE_DEBUG: environ, HOME: process.env.HOME }
-  });
+  var opt = {
+    env: process.env
+  };
+  opt.env.NODE_DEBUG = environ;
+  // Lttng requires the HOME env variable or it prints to stderr,
+  // This is not really ideal, as it breaks this test, so the HOME
+  // env variable is passed to the child to make the test pass.
+  // this is fixed in the next version of lttng (2.7+), so we can
+  // remove it at sometime in the future.
+  opt.env.HOME = process.env.HOME;
+  var child = spawn(process.execPath, [__filename, 'child'], opt);
 
   expectErr = expectErr.split('%PID%').join(child.pid);