diff --git a/doc/api/child_process.md b/doc/api/child_process.md
index c88443e078b0a6..38c94dbf908025 100644
--- a/doc/api/child_process.md
+++ b/doc/api/child_process.md
@@ -437,6 +437,8 @@ If not given, the default is to inherit the current working directory.
 Use `env` to specify environment variables that will be visible to the new
 process, the default is [`process.env`][].
 
+`undefined` values in `env` will be ignored.
+
 Example of running `ls -lh /usr`, capturing `stdout`, `stderr`, and the
 exit code:
 
diff --git a/lib/child_process.js b/lib/child_process.js
index d1c4d2f2903516..f2c1a0c237bd98 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -504,8 +504,11 @@ function normalizeSpawnArguments(file, args, options) {
   var env = options.env || process.env;
   var envPairs = [];
 
-  for (var key in env) {
-    envPairs.push(`${key}=${env[key]}`);
+  for (const key of Object.keys(env)) {
+    const value = env[key];
+    if (value !== undefined) {
+      envPairs.push(`${key}=${value}`);
+    }
   }
 
   _convertCustomFds(options);
diff --git a/test/parallel/test-child-process-env.js b/test/parallel/test-child-process-env.js
index 4582c48fda5db1..5bd02c24badef5 100644
--- a/test/parallel/test-child-process-env.js
+++ b/test/parallel/test-child-process-env.js
@@ -22,11 +22,15 @@
 'use strict';
 const common = require('../common');
 const assert = require('assert');
+const os = require('os');
 
 const spawn = require('child_process').spawn;
 
 const env = {
-  'HELLO': 'WORLD'
+  'HELLO': 'WORLD',
+  'UNDEFINED': undefined,
+  'NULL': null,
+  'EMPTY': ''
 };
 Object.setPrototypeOf(env, {
   'FOO': 'BAR'
@@ -53,5 +57,8 @@ child.stdout.on('data', function(chunk) {
 
 process.on('exit', function() {
   assert.ok(response.includes('HELLO=WORLD'));
-  assert.ok(response.includes('FOO=BAR'));
+  assert.ok(!response.includes('FOO='));
+  assert.ok(!response.includes('UNDEFINED=undefined'));
+  assert.ok(response.includes('NULL=null'));
+  assert.ok(response.includes(`EMPTY=${os.EOL}`));
 });