diff --git a/lib/internal/bootstrap/node.js b/lib/internal/bootstrap/node.js
index 358c4cb8c71b6c..071b68903d56d0 100644
--- a/lib/internal/bootstrap/node.js
+++ b/lib/internal/bootstrap/node.js
@@ -84,6 +84,8 @@ if (isMainThread) {
 } else {
   const wrapped = workerThreadSetup.wrapProcessMethods(rawMethods);
 
+  process.abort = workerThreadSetup.unavailable('process.abort()');
+  process.chdir = workerThreadSetup.unavailable('process.chdir()');
   process.umask = wrapped.umask;
 }
 
@@ -148,6 +150,14 @@ if (credentials.implementsPosixCredentials) {
     process.seteuid = wrapped.seteuid;
     process.setgid = wrapped.setgid;
     process.setuid = wrapped.setuid;
+  } else {
+    process.initgroups =
+      workerThreadSetup.unavailable('process.initgroups()');
+    process.setgroups = workerThreadSetup.unavailable('process.setgroups()');
+    process.setegid = workerThreadSetup.unavailable('process.setegid()');
+    process.seteuid = workerThreadSetup.unavailable('process.seteuid()');
+    process.setgid = workerThreadSetup.unavailable('process.setgid()');
+    process.setuid = workerThreadSetup.unavailable('process.setuid()');
   }
 }
 
@@ -174,8 +184,24 @@ if (config.hasInspector) {
 // This attaches some internal event listeners and creates:
 // process.send(), process.channel, process.connected,
 // process.disconnect()
-if (isMainThread && process.env.NODE_CHANNEL_FD) {
-  mainThreadSetup.setupChildProcessIpcChannel();
+if (process.env.NODE_CHANNEL_FD) {
+  if (ownsProcessState) {
+    mainThreadSetup.setupChildProcessIpcChannel();
+  } else {
+    Object.defineProperty(process, 'channel', {
+      enumerable: false,
+      get: workerThreadSetup.unavailable('process.channel')
+    });
+
+    Object.defineProperty(process, 'connected', {
+      enumerable: false,
+      get: workerThreadSetup.unavailable('process.connected')
+    });
+
+    process.send = workerThreadSetup.unavailable('process.send()');
+    process.disconnect =
+      workerThreadSetup.unavailable('process.disconnect()');
+  }
 }
 
 const browserGlobals = !process._noBrowserGlobals;
diff --git a/lib/internal/process/worker_thread_only.js b/lib/internal/process/worker_thread_only.js
index f05d5e932bebf2..2cc52cbf01b8cd 100644
--- a/lib/internal/process/worker_thread_only.js
+++ b/lib/internal/process/worker_thread_only.js
@@ -45,7 +45,17 @@ function wrapProcessMethods(binding) {
   return { umask };
 }
 
+function unavailable(name) {
+  function unavailableInWorker() {
+    throw new ERR_WORKER_UNSUPPORTED_OPERATION(name);
+  }
+
+  unavailableInWorker.disabled = true;
+  return unavailableInWorker;
+}
+
 module.exports = {
   initializeWorkerStdio,
+  unavailable,
   wrapProcessMethods
 };
diff --git a/test/parallel/test-process-euid-egid.js b/test/parallel/test-process-euid-egid.js
index 5639163bf31c13..b9e0630dab5eca 100644
--- a/test/parallel/test-process-euid-egid.js
+++ b/test/parallel/test-process-euid-egid.js
@@ -3,16 +3,17 @@
 const common = require('../common');
 const assert = require('assert');
 
-if (common.isWindows || !common.isMainThread) {
-  if (common.isMainThread) {
-    assert.strictEqual(process.geteuid, undefined);
-    assert.strictEqual(process.getegid, undefined);
-  }
+if (common.isWindows) {
+  assert.strictEqual(process.geteuid, undefined);
+  assert.strictEqual(process.getegid, undefined);
   assert.strictEqual(process.seteuid, undefined);
   assert.strictEqual(process.setegid, undefined);
   return;
 }
 
+if (!common.isMainThread)
+  return;
+
 assert.throws(() => {
   process.seteuid({});
 }, {
diff --git a/test/parallel/test-process-initgroups.js b/test/parallel/test-process-initgroups.js
index 49b8833f61a7bc..f5e839b1d242af 100644
--- a/test/parallel/test-process-initgroups.js
+++ b/test/parallel/test-process-initgroups.js
@@ -2,11 +2,14 @@
 const common = require('../common');
 const assert = require('assert');
 
-if (common.isWindows || !common.isMainThread) {
+if (common.isWindows) {
   assert.strictEqual(process.initgroups, undefined);
   return;
 }
 
+if (!common.isMainThread)
+  return;
+
 [undefined, null, true, {}, [], () => {}].forEach((val) => {
   assert.throws(
     () => {
diff --git a/test/parallel/test-process-setgroups.js b/test/parallel/test-process-setgroups.js
index a85d6683164a26..74de3e7a2562e7 100644
--- a/test/parallel/test-process-setgroups.js
+++ b/test/parallel/test-process-setgroups.js
@@ -2,11 +2,14 @@
 const common = require('../common');
 const assert = require('assert');
 
-if (common.isWindows || !common.isMainThread) {
+if (common.isWindows) {
   assert.strictEqual(process.setgroups, undefined);
   return;
 }
 
+if (!common.isMainThread)
+  return;
+
 assert.throws(
   () => {
     process.setgroups();
diff --git a/test/parallel/test-process-uid-gid.js b/test/parallel/test-process-uid-gid.js
index 456cba7f4dc027..49086792b9e7b1 100644
--- a/test/parallel/test-process-uid-gid.js
+++ b/test/parallel/test-process-uid-gid.js
@@ -24,17 +24,18 @@ const common = require('../common');
 
 const assert = require('assert');
 
-if (common.isWindows || !common.isMainThread) {
-  // uid/gid functions are POSIX only, setters are main-thread only.
-  if (common.isMainThread) {
-    assert.strictEqual(process.getuid, undefined);
-    assert.strictEqual(process.getgid, undefined);
-  }
+if (common.isWindows) {
+  // uid/gid functions are POSIX only.
+  assert.strictEqual(process.getuid, undefined);
+  assert.strictEqual(process.getgid, undefined);
   assert.strictEqual(process.setuid, undefined);
   assert.strictEqual(process.setgid, undefined);
   return;
 }
 
+if (!common.isMainThread)
+  return;
+
 assert.throws(() => {
   process.setuid({});
 }, {
diff --git a/test/parallel/test-worker-unsupported-things.js b/test/parallel/test-worker-unsupported-things.js
index 66b10ad1577d2c..cc9eec4af67760 100644
--- a/test/parallel/test-worker-unsupported-things.js
+++ b/test/parallel/test-worker-unsupported-things.js
@@ -1,9 +1,12 @@
 'use strict';
 const common = require('../common');
 const assert = require('assert');
-const { Worker, isMainThread, parentPort } = require('worker_threads');
+const { Worker, parentPort } = require('worker_threads');
 
-if (isMainThread) {
+// Do not use isMainThread so that this test itself can be run inside a Worker.
+if (!process.env.HAS_STARTED_WORKER) {
+  process.env.HAS_STARTED_WORKER = 1;
+  process.env.NODE_CHANNEL_FD = 'foo'; // Make worker think it has IPC.
   const w = new Worker(__filename);
   w.on('message', common.mustCall((message) => {
     assert.strictEqual(message, true);
@@ -21,14 +24,25 @@ if (isMainThread) {
     assert.strictEqual(process.debugPort, before);
   }
 
-  assert.strictEqual('abort' in process, false);
-  assert.strictEqual('chdir' in process, false);
-  assert.strictEqual('setuid' in process, false);
-  assert.strictEqual('seteuid' in process, false);
-  assert.strictEqual('setgid' in process, false);
-  assert.strictEqual('setegid' in process, false);
-  assert.strictEqual('setgroups' in process, false);
-  assert.strictEqual('initgroups' in process, false);
+  const stubs = ['abort', 'chdir', 'send', 'disconnect'];
+
+  if (!common.isWindows) {
+    stubs.push('setuid', 'seteuid', 'setgid',
+               'setegid', 'setgroups', 'initgroups');
+  }
+
+  stubs.forEach((fn) => {
+    assert.strictEqual(process[fn].disabled, true);
+    assert.throws(() => {
+      process[fn]();
+    }, { code: 'ERR_WORKER_UNSUPPORTED_OPERATION' });
+  });
+
+  ['channel', 'connected'].forEach((fn) => {
+    assert.throws(() => {
+      process[fn];
+    }, { code: 'ERR_WORKER_UNSUPPORTED_OPERATION' });
+  });
 
   assert.strictEqual('_startProfilerIdleNotifier' in process, false);
   assert.strictEqual('_stopProfilerIdleNotifier' in process, false);