diff --git a/doc/api/report.md b/doc/api/report.md
index b39a5286398b2c..b5ff3d8a88e3e5 100644
--- a/doc/api/report.md
+++ b/doc/api/report.md
@@ -296,6 +296,7 @@ is provided below for reference.
       "address": "0x000055fc7b2cb180"
     }
   ],
+  "workers": [],
   "environmentVariables": {
     "REMOTEHOST": "REMOVED",
     "MANPATH": "/opt/rh/devtoolset-3/root/usr/share/man:",
@@ -577,4 +578,24 @@ NODE_OPTIONS="--experimental-report --report-uncaught-exception \
 Specific API documentation can be found under
 [`process API documentation`][] section.
 
+## Interaction with Workers
+<!-- YAML
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/31386
+    description: Workers are now included in the report.
+-->
+
+[`Worker`][] threads can create reports in the same way that the main thread
+does.
+
+Reports will include information on any Workers that are children of the current
+thread as part of the `workers` section, with each Worker generating a report
+in the standard report format.
+
+The thread which is generating the report will wait for the reports from Worker
+threads to finish. However, the latency for this will usually be low, as both
+running JavaScript and the event loop are interrupted to generate the report.
+
 [`process API documentation`]: process.html
+[`Worker`]: worker_threads.html
diff --git a/src/env-inl.h b/src/env-inl.h
index cd111bc2641890..2002df9abaf1a4 100644
--- a/src/env-inl.h
+++ b/src/env-inl.h
@@ -242,14 +242,6 @@ inline bool ImmediateInfo::has_outstanding() const {
   return fields_[kHasOutstanding] == 1;
 }
 
-inline void ImmediateInfo::count_inc(uint32_t increment) {
-  fields_[kCount] += increment;
-}
-
-inline void ImmediateInfo::count_dec(uint32_t decrement) {
-  fields_[kCount] -= decrement;
-}
-
 inline void ImmediateInfo::ref_count_inc(uint32_t increment) {
   fields_[kRefCount] += increment;
 }
@@ -748,19 +740,51 @@ inline void IsolateData::set_options(
   options_ = std::move(options);
 }
 
-template <typename Fn>
-void Environment::CreateImmediate(Fn&& cb, bool ref) {
-  auto callback = std::make_unique<NativeImmediateCallbackImpl<Fn>>(
-      std::move(cb), ref);
-  NativeImmediateCallback* prev_tail = native_immediate_callbacks_tail_;
+std::unique_ptr<Environment::NativeImmediateCallback>
+Environment::NativeImmediateQueue::Shift() {
+  std::unique_ptr<Environment::NativeImmediateCallback> ret = std::move(head_);
+  if (ret) {
+    head_ = ret->get_next();
+    if (!head_)
+      tail_ = nullptr;  // The queue is now empty.
+  }
+  size_--;
+  return ret;
+}
 
-  native_immediate_callbacks_tail_ = callback.get();
+void Environment::NativeImmediateQueue::Push(
+    std::unique_ptr<Environment::NativeImmediateCallback> cb) {
+  NativeImmediateCallback* prev_tail = tail_;
+
+  size_++;
+  tail_ = cb.get();
   if (prev_tail != nullptr)
-    prev_tail->set_next(std::move(callback));
+    prev_tail->set_next(std::move(cb));
+  else
+    head_ = std::move(cb);
+}
+
+void Environment::NativeImmediateQueue::ConcatMove(
+    NativeImmediateQueue&& other) {
+  size_ += other.size_;
+  if (tail_ != nullptr)
+    tail_->set_next(std::move(other.head_));
   else
-    native_immediate_callbacks_head_ = std::move(callback);
+    head_ = std::move(other.head_);
+  tail_ = other.tail_;
+  other.tail_ = nullptr;
+  other.size_ = 0;
+}
 
-  immediate_info()->count_inc(1);
+size_t Environment::NativeImmediateQueue::size() const {
+  return size_.load();
+}
+
+template <typename Fn>
+void Environment::CreateImmediate(Fn&& cb, bool ref) {
+  auto callback = std::make_unique<NativeImmediateCallbackImpl<Fn>>(
+      std::move(cb), ref);
+  native_immediates_.Push(std::move(callback));
 }
 
 template <typename Fn>
@@ -777,6 +801,29 @@ void Environment::SetUnrefImmediate(Fn&& cb) {
   CreateImmediate(std::move(cb), false);
 }
 
+template <typename Fn>
+void Environment::SetImmediateThreadsafe(Fn&& cb) {
+  auto callback = std::make_unique<NativeImmediateCallbackImpl<Fn>>(
+      std::move(cb), false);
+  {
+    Mutex::ScopedLock lock(native_immediates_threadsafe_mutex_);
+    native_immediates_threadsafe_.Push(std::move(callback));
+  }
+  uv_async_send(&task_queues_async_);
+}
+
+template <typename Fn>
+void Environment::RequestInterrupt(Fn&& cb) {
+  auto callback = std::make_unique<NativeImmediateCallbackImpl<Fn>>(
+      std::move(cb), false);
+  {
+    Mutex::ScopedLock lock(native_immediates_threadsafe_mutex_);
+    native_immediates_interrupts_.Push(std::move(callback));
+  }
+  uv_async_send(&task_queues_async_);
+  RequestInterruptFromV8();
+}
+
 Environment::NativeImmediateCallback::NativeImmediateCallback(bool refed)
   : refed_(refed) {}
 
@@ -862,8 +909,26 @@ inline void Environment::remove_sub_worker_context(worker::Worker* context) {
   sub_worker_contexts_.erase(context);
 }
 
+template <typename Fn>
+inline void Environment::ForEachWorker(Fn&& iterator) {
+  for (worker::Worker* w : sub_worker_contexts_) iterator(w);
+}
+
+inline void Environment::add_refs(int64_t diff) {
+  task_queues_async_refs_ += diff;
+  CHECK_GE(task_queues_async_refs_, 0);
+  if (task_queues_async_refs_ == 0)
+    uv_unref(reinterpret_cast<uv_handle_t*>(&task_queues_async_));
+  else
+    uv_ref(reinterpret_cast<uv_handle_t*>(&task_queues_async_));
+}
+
 inline bool Environment::is_stopping() const {
-  return thread_stopper_.is_stopped();
+  return is_stopping_.load();
+}
+
+inline void Environment::set_stopping(bool value) {
+  is_stopping_.store(value);
 }
 
 inline std::list<node_module>* Environment::extra_linked_bindings() {
@@ -1146,7 +1211,7 @@ void Environment::RemoveCleanupHook(void (*fn)(void*), void* arg) {
 inline void Environment::RegisterFinalizationGroupForCleanup(
     v8::Local<v8::FinalizationGroup> group) {
   cleanup_finalization_groups_.emplace_back(isolate(), group);
-  uv_async_send(&cleanup_finalization_groups_async_);
+  uv_async_send(&task_queues_async_);
 }
 
 size_t CleanupHookCallback::Hash::operator()(
@@ -1183,14 +1248,6 @@ int64_t Environment::base_object_count() const {
   return base_object_count_;
 }
 
-bool AsyncRequest::is_stopped() const {
-  return stopped_.load();
-}
-
-void AsyncRequest::set_stopped(bool flag) {
-  stopped_.store(flag);
-}
-
 #define VP(PropertyName, StringValue) V(v8::Private, PropertyName)
 #define VY(PropertyName, StringValue) V(v8::Symbol, PropertyName)
 #define VS(PropertyName, StringValue) V(v8::String, PropertyName)
diff --git a/src/env.cc b/src/env.cc
index 51c5cc7c497f23..ba5e9cd5a05218 100644
--- a/src/env.cc
+++ b/src/env.cc
@@ -388,6 +388,8 @@ Environment::Environment(IsolateData* isolate_data,
 }
 
 Environment::~Environment() {
+  if (interrupt_data_ != nullptr) *interrupt_data_ = nullptr;
+
   isolate()->GetHeapProfiler()->RemoveBuildEmbedderGraphCallback(
       BuildEmbedderGraph, this);
 
@@ -460,23 +462,16 @@ void Environment::InitializeLibuv(bool start_profiler_idle_notifier) {
   uv_check_init(event_loop(), &idle_check_handle_);
   uv_async_init(
       event_loop(),
-      &cleanup_finalization_groups_async_,
+      &task_queues_async_,
       [](uv_async_t* async) {
         Environment* env = ContainerOf(
-            &Environment::cleanup_finalization_groups_async_, async);
+            &Environment::task_queues_async_, async);
         env->CleanupFinalizationGroups();
+        env->RunAndClearNativeImmediates();
       });
   uv_unref(reinterpret_cast<uv_handle_t*>(&idle_prepare_handle_));
   uv_unref(reinterpret_cast<uv_handle_t*>(&idle_check_handle_));
-  uv_unref(reinterpret_cast<uv_handle_t*>(&cleanup_finalization_groups_async_));
-
-  thread_stopper()->Install(
-    this, static_cast<void*>(this), [](uv_async_t* handle) {
-      Environment* env = static_cast<Environment*>(handle->data);
-      uv_stop(env->event_loop());
-    });
-  thread_stopper()->set_stopped(false);
-  uv_unref(reinterpret_cast<uv_handle_t*>(thread_stopper()->GetHandle()));
+  uv_unref(reinterpret_cast<uv_handle_t*>(&task_queues_async_));
 
   // Register clean-up cb to be called to clean up the handles
   // when the environment is freed, note that they are not cleaned in
@@ -495,8 +490,9 @@ void Environment::InitializeLibuv(bool start_profiler_idle_notifier) {
 
 void Environment::ExitEnv() {
   set_can_call_into_js(false);
-  thread_stopper()->Stop();
+  set_stopping(true);
   isolate_->TerminateExecution();
+  SetImmediateThreadsafe([](Environment* env) { uv_stop(env->event_loop()); });
 }
 
 void Environment::RegisterHandleCleanups() {
@@ -532,7 +528,7 @@ void Environment::RegisterHandleCleanups() {
       close_and_finish,
       nullptr);
   RegisterHandleCleanup(
-      reinterpret_cast<uv_handle_t*>(&cleanup_finalization_groups_async_),
+      reinterpret_cast<uv_handle_t*>(&task_queues_async_),
       close_and_finish,
       nullptr);
 }
@@ -601,7 +597,6 @@ void Environment::RunCleanup() {
   started_cleanup_ = true;
   TraceEventScope trace_scope(TRACING_CATEGORY_NODE1(environment),
                               "RunCleanup", this);
-  thread_stopper()->Uninstall();
   CleanupHandles();
 
   while (!cleanup_hooks_.empty()) {
@@ -658,20 +653,45 @@ void Environment::AtExit(void (*cb)(void* arg), void* arg) {
   at_exit_functions_.push_front(ExitCallback{cb, arg});
 }
 
+void Environment::RunAndClearInterrupts() {
+  while (native_immediates_interrupts_.size() > 0) {
+    NativeImmediateQueue queue;
+    {
+      Mutex::ScopedLock lock(native_immediates_threadsafe_mutex_);
+      queue.ConcatMove(std::move(native_immediates_interrupts_));
+    }
+    DebugSealHandleScope seal_handle_scope(isolate());
+
+    while (std::unique_ptr<NativeImmediateCallback> head = queue.Shift())
+      head->Call(this);
+  }
+}
+
 void Environment::RunAndClearNativeImmediates(bool only_refed) {
   TraceEventScope trace_scope(TRACING_CATEGORY_NODE1(environment),
                               "RunAndClearNativeImmediates", this);
   size_t ref_count = 0;
-  size_t count = 0;
-  std::unique_ptr<NativeImmediateCallback> head;
-  head.swap(native_immediate_callbacks_head_);
-  native_immediate_callbacks_tail_ = nullptr;
+
+  // Handle interrupts first. These functions are not allowed to throw
+  // exceptions, so we do not need to handle that.
+  RunAndClearInterrupts();
+
+  // It is safe to check .size() first, because there is a causal relationship
+  // between pushes to the threadsafe and this function being called.
+  // For the common case, it's worth checking the size first before establishing
+  // a mutex lock.
+  if (native_immediates_threadsafe_.size() > 0) {
+    Mutex::ScopedLock lock(native_immediates_threadsafe_mutex_);
+    native_immediates_.ConcatMove(std::move(native_immediates_threadsafe_));
+  }
+
+  NativeImmediateQueue queue;
+  queue.ConcatMove(std::move(native_immediates_));
 
   auto drain_list = [&]() {
     TryCatchScope try_catch(this);
-    for (; head; head = head->get_next()) {
-      DebugSealHandleScope seal_handle_scope(isolate());
-      count++;
+    DebugSealHandleScope seal_handle_scope(isolate());
+    while (std::unique_ptr<NativeImmediateCallback> head = queue.Shift()) {
       if (head->is_refed())
         ref_count++;
 
@@ -682,21 +702,40 @@ void Environment::RunAndClearNativeImmediates(bool only_refed) {
         if (!try_catch.HasTerminated() && can_call_into_js())
           errors::TriggerUncaughtException(isolate(), try_catch);
 
-        // We are done with the current callback. Move one iteration along,
-        // as if we had completed successfully.
-        head = head->get_next();
         return true;
       }
     }
     return false;
   };
-  while (head && drain_list()) {}
+  while (queue.size() > 0 && drain_list()) {}
 
-  DCHECK_GE(immediate_info()->count(), count);
-  immediate_info()->count_dec(count);
   immediate_info()->ref_count_dec(ref_count);
+
+  if (immediate_info()->ref_count() == 0)
+    ToggleImmediateRef(false);
 }
 
+void Environment::RequestInterruptFromV8() {
+  if (interrupt_data_ != nullptr) return;  // Already scheduled.
+
+  // The Isolate may outlive the Environment, so some logic to handle the
+  // situation in which the Environment is destroyed before the handler runs
+  // is required.
+  interrupt_data_ = new Environment*(this);
+
+  isolate()->RequestInterrupt([](Isolate* isolate, void* data) {
+    std::unique_ptr<Environment*> env_ptr { static_cast<Environment**>(data) };
+    Environment* env = *env_ptr;
+    if (env == nullptr) {
+      // The Environment has already been destroyed. That should be okay; any
+      // callback added before the Environment shuts down would have been
+      // handled during cleanup.
+      return;
+    }
+    env->interrupt_data_ = nullptr;
+    env->RunAndClearInterrupts();
+  }, interrupt_data_);
+}
 
 void Environment::ScheduleTimer(int64_t duration_ms) {
   if (started_cleanup_) return;
@@ -780,15 +819,12 @@ void Environment::CheckImmediate(uv_check_t* handle) {
   TraceEventScope trace_scope(TRACING_CATEGORY_NODE1(environment),
                               "CheckImmediate", env);
 
-  if (env->immediate_info()->count() == 0)
-    return;
-
   HandleScope scope(env->isolate());
   Context::Scope context_scope(env->context());
 
   env->RunAndClearNativeImmediates();
 
-  if (!env->can_call_into_js())
+  if (env->immediate_info()->count() == 0 || !env->can_call_into_js())
     return;
 
   do {
@@ -1011,7 +1047,6 @@ inline size_t Environment::SelfSize() const {
   // TODO(joyeecheung): refactor the MemoryTracker interface so
   // this can be done for common types within the Track* calls automatically
   // if a certain scope is entered.
-  size -= sizeof(thread_stopper_);
   size -= sizeof(async_hooks_);
   size -= sizeof(tick_info_);
   size -= sizeof(immediate_info_);
@@ -1033,7 +1068,6 @@ void Environment::MemoryInfo(MemoryTracker* tracker) const {
   tracker->TrackField("fs_stats_field_array", fs_stats_field_array_);
   tracker->TrackField("fs_stats_field_bigint_array",
                       fs_stats_field_bigint_array_);
-  tracker->TrackField("thread_stopper", thread_stopper_);
   tracker->TrackField("cleanup_hooks", cleanup_hooks_);
   tracker->TrackField("async_hooks", async_hooks_);
   tracker->TrackField("immediate_info", immediate_info_);
@@ -1091,44 +1125,12 @@ void Environment::CleanupFinalizationGroups() {
       if (try_catch.HasCaught() && !try_catch.HasTerminated())
         errors::TriggerUncaughtException(isolate(), try_catch);
       // Re-schedule the execution of the remainder of the queue.
-      uv_async_send(&cleanup_finalization_groups_async_);
+      uv_async_send(&task_queues_async_);
       return;
     }
   }
 }
 
-void AsyncRequest::Install(Environment* env, void* data, uv_async_cb target) {
-  CHECK_NULL(async_);
-  env_ = env;
-  async_ = new uv_async_t;
-  async_->data = data;
-  CHECK_EQ(uv_async_init(env_->event_loop(), async_, target), 0);
-}
-
-void AsyncRequest::Uninstall() {
-  if (async_ != nullptr) {
-    env_->CloseHandle(async_, [](uv_async_t* async) { delete async; });
-    async_ = nullptr;
-  }
-}
-
-void AsyncRequest::Stop() {
-  set_stopped(true);
-  if (async_ != nullptr) uv_async_send(async_);
-}
-
-uv_async_t* AsyncRequest::GetHandle() {
-  return async_;
-}
-
-void AsyncRequest::MemoryInfo(MemoryTracker* tracker) const {
-  if (async_ != nullptr) tracker->TrackField("async_request", *async_);
-}
-
-AsyncRequest::~AsyncRequest() {
-  CHECK_NULL(async_);
-}
-
 // Not really any better place than env.cc at this moment.
 void BaseObject::DeleteMe(void* data) {
   BaseObject* self = static_cast<BaseObject*>(data);
diff --git a/src/env.h b/src/env.h
index fcba4dcde67f53..1f8442d478b585 100644
--- a/src/env.h
+++ b/src/env.h
@@ -587,34 +587,6 @@ struct AllocatedBuffer {
   friend class Environment;
 };
 
-class AsyncRequest : public MemoryRetainer {
- public:
-  AsyncRequest() = default;
-  ~AsyncRequest() override;
-
-  AsyncRequest(const AsyncRequest&) = delete;
-  AsyncRequest& operator=(const AsyncRequest&) = delete;
-  AsyncRequest(AsyncRequest&&) = delete;
-  AsyncRequest& operator=(AsyncRequest&&) = delete;
-
-  void Install(Environment* env, void* data, uv_async_cb target);
-  void Uninstall();
-  void Stop();
-  inline void set_stopped(bool flag);
-  inline bool is_stopped() const;
-  uv_async_t* GetHandle();
-  void MemoryInfo(MemoryTracker* tracker) const override;
-
-
-  SET_MEMORY_INFO_NAME(AsyncRequest)
-  SET_SELF_SIZE(AsyncRequest)
-
- private:
-  Environment* env_;
-  uv_async_t* async_ = nullptr;
-  std::atomic_bool stopped_ {true};
-};
-
 class KVStore {
  public:
   KVStore() = default;
@@ -736,8 +708,6 @@ class ImmediateInfo : public MemoryRetainer {
   inline uint32_t count() const;
   inline uint32_t ref_count() const;
   inline bool has_outstanding() const;
-  inline void count_inc(uint32_t increment);
-  inline void count_dec(uint32_t decrement);
   inline void ref_count_inc(uint32_t increment);
   inline void ref_count_dec(uint32_t decrement);
 
@@ -1067,6 +1037,14 @@ class Environment : public MemoryRetainer {
   inline bool can_call_into_js() const;
   inline void set_can_call_into_js(bool can_call_into_js);
 
+  // Increase or decrease a counter that manages whether this Environment
+  // keeps the event loop alive on its own or not. The counter starts out at 0,
+  // meaning it does not, and any positive value will make it keep the event
+  // loop alive.
+  // This is used by Workers to manage their own .ref()/.unref() implementation,
+  // as Workers aren't directly associated with their own libuv handles.
+  inline void add_refs(int64_t diff);
+
   inline bool has_run_bootstrapping_code() const;
   inline void set_has_run_bootstrapping_code(bool has_run_bootstrapping_code);
 
@@ -1086,7 +1064,10 @@ class Environment : public MemoryRetainer {
   inline void add_sub_worker_context(worker::Worker* context);
   inline void remove_sub_worker_context(worker::Worker* context);
   void stop_sub_worker_contexts();
+  template <typename Fn>
+  inline void ForEachWorker(Fn&& iterator);
   inline bool is_stopping() const;
+  inline void set_stopping(bool value);
   inline std::list<node_module>* extra_linked_bindings();
   inline node_module* extra_linked_bindings_head();
   inline const Mutex& extra_linked_bindings_mutex() const;
@@ -1201,6 +1182,15 @@ class Environment : public MemoryRetainer {
   inline void SetImmediate(Fn&& cb);
   template <typename Fn>
   inline void SetUnrefImmediate(Fn&& cb);
+  template <typename Fn>
+  // This behaves like SetImmediate() but can be called from any thread.
+  inline void SetImmediateThreadsafe(Fn&& cb);
+  // This behaves like V8's Isolate::RequestInterrupt(), but also accounts for
+  // the event loop (i.e. combines the V8 function with SetImmediate()).
+  // The passed callback may not throw exceptions.
+  // This function can be called from any thread.
+  template <typename Fn>
+  inline void RequestInterrupt(Fn&& cb);
   // This needs to be available for the JS-land setImmediate().
   void ToggleImmediateRef(bool ref);
 
@@ -1225,8 +1215,6 @@ class Environment : public MemoryRetainer {
   inline std::shared_ptr<EnvironmentOptions> options();
   inline std::shared_ptr<HostPort> inspector_host_port();
 
-  inline AsyncRequest* thread_stopper() { return &thread_stopper_; }
-
   // The BaseObject count is a debugging helper that makes sure that there are
   // no memory leaks caused by BaseObjects staying alive longer than expected
   // (in particular, no circular BaseObjectPtr references).
@@ -1286,7 +1274,8 @@ class Environment : public MemoryRetainer {
   uv_idle_t immediate_idle_handle_;
   uv_prepare_t idle_prepare_handle_;
   uv_check_t idle_check_handle_;
-  uv_async_t cleanup_finalization_groups_async_;
+  uv_async_t task_queues_async_;
+  int64_t task_queues_async_refs_ = 0;
   bool profiler_idle_notifier_started_ = false;
 
   AsyncHooks async_hooks_;
@@ -1344,7 +1333,7 @@ class Environment : public MemoryRetainer {
   bool has_run_bootstrapping_code_ = false;
   bool has_serialized_options_ = false;
 
-  bool can_call_into_js_ = true;
+  std::atomic_bool can_call_into_js_ { true };
   Flags flags_;
   uint64_t thread_id_;
   std::unordered_set<worker::Worker*> sub_worker_contexts_;
@@ -1430,10 +1419,32 @@ class Environment : public MemoryRetainer {
     Fn callback_;
   };
 
-  std::unique_ptr<NativeImmediateCallback> native_immediate_callbacks_head_;
-  NativeImmediateCallback* native_immediate_callbacks_tail_ = nullptr;
+  class NativeImmediateQueue {
+   public:
+    inline std::unique_ptr<NativeImmediateCallback> Shift();
+    inline void Push(std::unique_ptr<NativeImmediateCallback> cb);
+    // ConcatMove adds elements from 'other' to the end of this list, and clears
+    // 'other' afterwards.
+    inline void ConcatMove(NativeImmediateQueue&& other);
+
+    // size() is atomic and may be called from any thread.
+    inline size_t size() const;
+
+   private:
+    std::atomic<size_t> size_ {0};
+    std::unique_ptr<NativeImmediateCallback> head_;
+    NativeImmediateCallback* tail_ = nullptr;
+  };
+
+  NativeImmediateQueue native_immediates_;
+  Mutex native_immediates_threadsafe_mutex_;
+  NativeImmediateQueue native_immediates_threadsafe_;
+  NativeImmediateQueue native_immediates_interrupts_;
 
   void RunAndClearNativeImmediates(bool only_refed = false);
+  void RunAndClearInterrupts();
+  Environment** interrupt_data_ = nullptr;
+  void RequestInterruptFromV8();
   static void CheckImmediate(uv_check_t* handle);
 
   // Use an unordered_set, so that we have efficient insertion and removal.
@@ -1444,10 +1455,7 @@ class Environment : public MemoryRetainer {
   bool started_cleanup_ = false;
 
   int64_t base_object_count_ = 0;
-
-  // A custom async abstraction (a pair of async handle and a state variable)
-  // Used by embedders to shutdown running Node instance.
-  AsyncRequest thread_stopper_;
+  std::atomic_bool is_stopping_ { false };
 
   template <typename T>
   void ForEachBaseObject(T&& iterator);
diff --git a/src/node_messaging.cc b/src/node_messaging.cc
index 1028da69b44961..ebad6c67508105 100644
--- a/src/node_messaging.cc
+++ b/src/node_messaging.cc
@@ -900,6 +900,10 @@ void MessagePort::Entangle(MessagePort* a, MessagePortData* b) {
   MessagePortData::Entangle(a->data_.get(), b);
 }
 
+void MessagePort::MemoryInfo(MemoryTracker* tracker) const {
+  tracker->TrackField("data", data_);
+}
+
 Local<FunctionTemplate> GetMessagePortConstructorTemplate(Environment* env) {
   // Factor generating the MessagePort JS constructor into its own piece
   // of code, because it is needed early on in the child environment setup.
diff --git a/src/node_messaging.h b/src/node_messaging.h
index 526158e144d354..6d2410a7248b95 100644
--- a/src/node_messaging.h
+++ b/src/node_messaging.h
@@ -191,10 +191,7 @@ class MessagePort : public HandleWrap {
   // NULL pointer to the C++ MessagePort object is also detached.
   inline bool IsDetached() const;
 
-  void MemoryInfo(MemoryTracker* tracker) const override {
-    tracker->TrackField("data", data_);
-  }
-
+  void MemoryInfo(MemoryTracker* tracker) const override;
   SET_MEMORY_INFO_NAME(MessagePort)
   SET_SELF_SIZE(MessagePort)
 
diff --git a/src/node_report.cc b/src/node_report.cc
index ddeb216c82d6bc..9b32352326becf 100644
--- a/src/node_report.cc
+++ b/src/node_report.cc
@@ -4,6 +4,8 @@
 #include "diagnosticfilename-inl.h"
 #include "node_internals.h"
 #include "node_metadata.h"
+#include "node_mutex.h"
+#include "node_worker.h"
 #include "util.h"
 
 #ifdef _WIN32
@@ -19,18 +21,20 @@
 #include <cwctype>
 #include <fstream>
 
-constexpr int NODE_REPORT_VERSION = 1;
+constexpr int NODE_REPORT_VERSION = 2;
 constexpr int NANOS_PER_SEC = 1000 * 1000 * 1000;
 constexpr double SEC_PER_MICROS = 1e-6;
 
 namespace report {
 using node::arraysize;
+using node::ConditionVariable;
 using node::DiagnosticFilename;
 using node::Environment;
 using node::Mutex;
 using node::NativeSymbolDebuggingContext;
 using node::PerIsolateOptions;
 using node::TIME_TYPE;
+using node::worker::Worker;
 using v8::HeapSpaceStatistics;
 using v8::HeapStatistics;
 using v8::Isolate;
@@ -210,6 +214,10 @@ static void WriteNodeReport(Isolate* isolate,
 
   // Report native process ID
   writer.json_keyvalue("processId", pid);
+  if (env != nullptr)
+    writer.json_keyvalue("threadId", env->thread_id());
+  else
+    writer.json_keyvalue("threadId", JSONWriter::Null{});
 
   {
     // Report the process cwd.
@@ -259,6 +267,39 @@ static void WriteNodeReport(Isolate* isolate,
 
   writer.json_arrayend();
 
+  writer.json_arraystart("workers");
+  if (env != nullptr) {
+    Mutex workers_mutex;
+    ConditionVariable notify;
+    std::vector<std::string> worker_infos;
+    size_t expected_results = 0;
+
+    env->ForEachWorker([&](Worker* w) {
+      expected_results += w->RequestInterrupt([&](Environment* env) {
+        std::ostringstream os;
+
+        GetNodeReport(env->isolate(),
+                      env,
+                      "Worker thread subreport",
+                      trigger,
+                      Local<String>(),
+                      os);
+
+        Mutex::ScopedLock lock(workers_mutex);
+        worker_infos.emplace_back(os.str());
+        notify.Signal(lock);
+      });
+    });
+
+    Mutex::ScopedLock lock(workers_mutex);
+    worker_infos.reserve(expected_results);
+    while (worker_infos.size() < expected_results)
+      notify.Wait(lock);
+    for (const std::string& worker_info : worker_infos)
+      writer.json_element(JSONWriter::ForeignJSON { worker_info });
+  }
+  writer.json_arrayend();
+
   // Report operating system information
   PrintSystemInformation(&writer);
 
diff --git a/src/node_report.h b/src/node_report.h
index 4cb82470f43594..46b69b9681db51 100644
--- a/src/node_report.h
+++ b/src/node_report.h
@@ -44,6 +44,7 @@ void GetNodeReport(v8::Isolate* isolate,
 // Function declarations - utility functions in src/node_report_utils.cc
 void WalkHandle(uv_handle_t* h, void* arg);
 std::string EscapeJsonChars(const std::string& str);
+std::string Reindent(const std::string& str, int indentation);
 
 template <typename T>
 std::string ValueToHexString(T value) {
@@ -146,6 +147,10 @@ class JSONWriter {
 
   struct Null {};  // Usable as a JSON value.
 
+  struct ForeignJSON {
+    std::string as_string;
+  };
+
  private:
   template <typename T,
             typename test_for_number = typename std::
@@ -161,6 +166,10 @@ class JSONWriter {
   inline void write_value(const char* str) { write_string(str); }
   inline void write_value(const std::string& str) { write_string(str); }
 
+  inline void write_value(const ForeignJSON& json) {
+    out_ << Reindent(json.as_string, indent_);
+  }
+
   inline void write_string(const std::string& str) {
     out_ << '"' << EscapeJsonChars(str) << '"';
   }
diff --git a/src/node_report_utils.cc b/src/node_report_utils.cc
index 33d7c52b34f78e..efa15790b9bc96 100644
--- a/src/node_report_utils.cc
+++ b/src/node_report_utils.cc
@@ -263,4 +263,28 @@ std::string EscapeJsonChars(const std::string& str) {
   return ret;
 }
 
+std::string Reindent(const std::string& str, int indent_depth) {
+  std::string indent;
+  for (int i = 0; i < indent_depth; i++) indent += ' ';
+
+  std::string out;
+  std::string::size_type pos = 0;
+  do {
+    std::string::size_type prev_pos = pos;
+    pos = str.find('\n', pos);
+
+    out.append(indent);
+
+    if (pos == std::string::npos) {
+      out.append(str, prev_pos, std::string::npos);
+      break;
+    } else {
+      pos++;
+      out.append(str, prev_pos, pos - prev_pos);
+    }
+  } while (true);
+
+  return out;
+}
+
 }  // namespace report
diff --git a/src/node_worker.cc b/src/node_worker.cc
index 2f43780a951ad4..785f2783c22346 100644
--- a/src/node_worker.cc
+++ b/src/node_worker.cc
@@ -268,7 +268,7 @@ void Worker::Run() {
           stopped_ = true;
           this->env_ = nullptr;
         }
-        env_->thread_stopper()->set_stopped(true);
+        env_->set_stopping(true);
         env_->stop_sub_worker_contexts();
         env_->RunCleanup();
         RunAtExit(env_.get());
@@ -412,7 +412,6 @@ void Worker::JoinThread() {
   thread_joined_ = true;
 
   env()->remove_sub_worker_context(this);
-  on_thread_finished_.Uninstall();
 
   {
     HandleScope handle_scope(env()->isolate());
@@ -439,6 +438,8 @@ void Worker::JoinThread() {
 }
 
 Worker::~Worker() {
+  JoinThread();
+
   Mutex::ScopedLock lock(mutex_);
 
   CHECK(stopped_);
@@ -574,18 +575,16 @@ void Worker::StartThread(const FunctionCallbackInfo<Value>& args) {
   w->stopped_ = false;
   w->thread_joined_ = false;
 
-  w->on_thread_finished_.Install(w->env(), w, [](uv_async_t* handle) {
-    Worker* w_ = static_cast<Worker*>(handle->data);
-    CHECK(w_->is_stopped());
-    w_->parent_port_ = nullptr;
-    w_->JoinThread();
-    delete w_;
-  });
+  if (w->has_ref_)
+    w->env()->add_refs(1);
 
   uv_thread_options_t thread_options;
   thread_options.flags = UV_THREAD_HAS_STACK_SIZE;
   thread_options.stack_size = kStackSize;
   CHECK_EQ(uv_thread_create_ex(&w->tid_, &thread_options, [](void* arg) {
+    // XXX: This could become a std::unique_ptr, but that makes at least
+    // gcc 6.3 detect undefined behaviour when there shouldn't be any.
+    // gcc 7+ handles this well.
     Worker* w = static_cast<Worker*>(arg);
     const uintptr_t stack_top = reinterpret_cast<uintptr_t>(&arg);
 
@@ -596,7 +595,12 @@ void Worker::StartThread(const FunctionCallbackInfo<Value>& args) {
     w->Run();
 
     Mutex::ScopedLock lock(w->mutex_);
-    w->on_thread_finished_.Stop();
+    w->env()->SetImmediateThreadsafe(
+        [w = std::unique_ptr<Worker>(w)](Environment* env) {
+          if (w->has_ref_)
+            env->add_refs(-1);
+          // implicitly delete w
+        });
   }, static_cast<void*>(w)), 0);
 }
 
@@ -611,13 +615,19 @@ void Worker::StopThread(const FunctionCallbackInfo<Value>& args) {
 void Worker::Ref(const FunctionCallbackInfo<Value>& args) {
   Worker* w;
   ASSIGN_OR_RETURN_UNWRAP(&w, args.This());
-  uv_ref(reinterpret_cast<uv_handle_t*>(w->on_thread_finished_.GetHandle()));
+  if (!w->has_ref_) {
+    w->has_ref_ = true;
+    w->env()->add_refs(1);
+  }
 }
 
 void Worker::Unref(const FunctionCallbackInfo<Value>& args) {
   Worker* w;
   ASSIGN_OR_RETURN_UNWRAP(&w, args.This());
-  uv_unref(reinterpret_cast<uv_handle_t*>(w->on_thread_finished_.GetHandle()));
+  if (w->has_ref_) {
+    w->has_ref_ = false;
+    w->env()->add_refs(-1);
+  }
 }
 
 void Worker::GetResourceLimits(const FunctionCallbackInfo<Value>& args) {
@@ -646,6 +656,10 @@ void Worker::Exit(int code) {
   }
 }
 
+void Worker::MemoryInfo(MemoryTracker* tracker) const {
+  tracker->TrackField("parent_port", parent_port_);
+}
+
 namespace {
 
 // Return the MessagePort that is global for this Environment and communicates
diff --git a/src/node_worker.h b/src/node_worker.h
index 7b1311734a2a4a..f84362f35c1897 100644
--- a/src/node_worker.h
+++ b/src/node_worker.h
@@ -39,11 +39,10 @@ class Worker : public AsyncWrap {
   // Wait for the worker thread to stop (in a blocking manner).
   void JoinThread();
 
-  void MemoryInfo(MemoryTracker* tracker) const override {
-    tracker->TrackField("parent_port", parent_port_);
-    tracker->TrackInlineField(&on_thread_finished_, "on_thread_finished_");
-  }
+  template <typename Fn>
+  inline bool RequestInterrupt(Fn&& cb);
 
+  void MemoryInfo(MemoryTracker* tracker) const override;
   SET_MEMORY_INFO_NAME(Worker)
   SET_SELF_SIZE(Worker)
 
@@ -107,14 +106,14 @@ class Worker : public AsyncWrap {
   // instance refers to it via its [kPort] property.
   MessagePort* parent_port_ = nullptr;
 
-  AsyncRequest on_thread_finished_;
-
   // A raw flag that is used by creator and worker threads to
   // sync up on pre-mature termination of worker  - while in the
   // warmup phase.  Once the worker is fully warmed up, use the
   // async handle of the worker's Environment for the same purpose.
   bool stopped_ = true;
 
+  bool has_ref_ = true;
+
   // The real Environment of the worker object. It has a lesser
   // lifespan than the worker object itself - comes to life
   // when the worker thread creates a new Environment, and gets
@@ -124,6 +123,14 @@ class Worker : public AsyncWrap {
   friend class WorkerThreadData;
 };
 
+template <typename Fn>
+bool Worker::RequestInterrupt(Fn&& cb) {
+  Mutex::ScopedLock lock(mutex_);
+  if (env_ == nullptr) return false;
+  env_->RequestInterrupt(std::move(cb));
+  return true;
+}
+
 }  // namespace worker
 }  // namespace node
 
diff --git a/test/common/report.js b/test/common/report.js
index fdb15924cab770..c117d7b76459bc 100644
--- a/test/common/report.js
+++ b/test/common/report.js
@@ -53,7 +53,7 @@ function _validateContent(report) {
   // Verify that all sections are present as own properties of the report.
   const sections = ['header', 'javascriptStack', 'nativeStack',
                     'javascriptHeap', 'libuv', 'environmentVariables',
-                    'sharedObjects', 'resourceUsage'];
+                    'sharedObjects', 'resourceUsage', 'workers'];
   if (!isWindows)
     sections.push('userLimits');
 
@@ -74,9 +74,9 @@ function _validateContent(report) {
                         'componentVersions', 'release', 'osName', 'osRelease',
                         'osVersion', 'osMachine', 'cpus', 'host',
                         'glibcVersionRuntime', 'glibcVersionCompiler', 'cwd',
-                        'reportVersion', 'networkInterfaces'];
+                        'reportVersion', 'networkInterfaces', 'threadId'];
   checkForUnknownFields(header, headerFields);
-  assert.strictEqual(header.reportVersion, 1);  // Increment as needed.
+  assert.strictEqual(header.reportVersion, 2);  // Increment as needed.
   assert.strictEqual(typeof header.event, 'string');
   assert.strictEqual(typeof header.trigger, 'string');
   assert(typeof header.filename === 'string' || header.filename === null);
@@ -84,6 +84,7 @@ function _validateContent(report) {
                         'Invalid Date');
   assert(String(+header.dumpEventTimeStamp), header.dumpEventTimeStamp);
   assert(Number.isSafeInteger(header.processId));
+  assert(Number.isSafeInteger(header.threadId) || header.threadId === null);
   assert.strictEqual(typeof header.cwd, 'string');
   assert(Array.isArray(header.commandLine));
   header.commandLine.forEach((arg) => {
@@ -253,6 +254,10 @@ function _validateContent(report) {
   report.sharedObjects.forEach((sharedObject) => {
     assert.strictEqual(typeof sharedObject, 'string');
   });
+
+  // Verify the format of the workers section.
+  assert(Array.isArray(report.workers));
+  report.workers.forEach(_validateContent);
 }
 
 function checkForUnknownFields(actual, expected) {
diff --git a/test/report/test-report-worker.js b/test/report/test-report-worker.js
new file mode 100644
index 00000000000000..a34c05f08431de
--- /dev/null
+++ b/test/report/test-report-worker.js
@@ -0,0 +1,50 @@
+// Flags: --experimental-report
+'use strict';
+const common = require('../common');
+common.skipIfReportDisabled();
+const assert = require('assert');
+const { Worker } = require('worker_threads');
+const { once } = require('events');
+const helper = require('../common/report');
+
+async function basic() {
+  // Test that the report includes basic information about Worker threads.
+
+  const w = new Worker(`
+    const { parentPort } = require('worker_threads');
+    parentPort.once('message', () => {
+      /* Wait for message to stop the Worker */
+    });
+  `, { eval: true });
+
+  await once(w, 'online');
+
+  const report = process.report.getReport();
+  helper.validateContent(report);
+  assert.strictEqual(report.workers.length, 1);
+  helper.validateContent(report.workers[0]);
+
+  w.postMessage({});
+
+  await once(w, 'exit');
+}
+
+async function interruptingJS() {
+  // Test that the report also works when Worker threads are busy in JS land.
+
+  const w = new Worker('while (true);', { eval: true });
+
+  await once(w, 'online');
+
+  const report = process.report.getReport();
+  helper.validateContent(report);
+  assert.strictEqual(report.workers.length, 1);
+  helper.validateContent(report.workers[0]);
+
+  await w.terminate();
+}
+
+(async function() {
+  await basic();
+  await interruptingJS();
+})().then(common.mustCall());