diff --git a/browser/devtools/debugger/test/browser.ini b/browser/devtools/debugger/test/browser.ini
index 0fa4d0beaeda..467e6f47d64f 100644
--- a/browser/devtools/debugger/test/browser.ini
+++ b/browser/devtools/debugger/test/browser.ini
@@ -43,6 +43,8 @@ support-files =
   code_ugly-7.js
   code_ugly-8
   code_ugly-8^headers^
+  code_WorkerActor.attach-worker1.js
+  code_WorkerActor.attach-worker2.js
   doc_auto-pretty-print-01.html
   doc_auto-pretty-print-02.html
   doc_binary_search.html
@@ -103,6 +105,8 @@ support-files =
   doc_watch-expressions.html
   doc_watch-expression-button.html
   doc_with-frame.html
+  doc_WorkerActor.attach-tab1.html
+  doc_WorkerActor.attach-tab2.html
   head.js
   sjs_random-javascript.sjs
   testactors.js
@@ -556,3 +560,5 @@ skip-if = e10s && debug
 skip-if = e10s && debug
 [browser_dbg_watch-expressions-02.js]
 skip-if = e10s && debug
+[browser_dbg_WorkerActor.attach.js]
+skip-if = e10s && debug
diff --git a/browser/devtools/debugger/test/browser_dbg_WorkerActor.attach.js b/browser/devtools/debugger/test/browser_dbg_WorkerActor.attach.js
new file mode 100644
index 000000000000..fe0d839518c5
--- /dev/null
+++ b/browser/devtools/debugger/test/browser_dbg_WorkerActor.attach.js
@@ -0,0 +1,63 @@
+let MAX_TOTAL_VIEWERS = "browser.sessionhistory.max_total_viewers";
+
+let TAB1_URL = EXAMPLE_URL + "doc_WorkerActor.attach-tab1.html";
+let TAB2_URL = EXAMPLE_URL + "doc_WorkerActor.attach-tab2.html";
+let WORKER1_URL = "code_WorkerActor.attach-worker1.js";
+let WORKER2_URL = "code_WorkerActor.attach-worker2.js";
+
+function test() {
+  Task.spawn(function* () {
+    let oldMaxTotalViewers = SpecialPowers.getIntPref(MAX_TOTAL_VIEWERS);
+    SpecialPowers.setIntPref(MAX_TOTAL_VIEWERS, 10);
+
+    DebuggerServer.init();
+    DebuggerServer.addBrowserActors();
+
+    let client = new DebuggerClient(DebuggerServer.connectPipe());
+    yield connect(client);
+
+    let tab = yield addTab(TAB1_URL);
+    let { tabs } = yield listTabs(client);
+    let [, tabClient] = yield attachTab(client, findTab(tabs, TAB1_URL));
+    yield listWorkers(tabClient);
+
+    // If a page still has pending network requests, it will not be moved into
+    // the bfcache. Consequently, we cannot use waitForWorkerListChanged here,
+    // because the worker is not guaranteed to have finished loading when it is
+    // registered. Instead, we have to wait for the promise returned by
+    // createWorker in the tab to be resolved.
+    yield createWorkerInTab(tab, WORKER1_URL);
+
+    let { workers } = yield listWorkers(tabClient);
+    let [, workerClient1] = yield attachWorker(tabClient,
+                                               findWorker(workers, WORKER1_URL));
+    is(workerClient1.isFrozen, false);
+
+    executeSoon(() => {
+      tab.linkedBrowser.loadURI(TAB2_URL);
+    });
+    yield waitForWorkerFreeze(workerClient1);
+    is(workerClient1.isFrozen, true, "worker should be frozen");
+
+    yield createWorkerInTab(tab, WORKER2_URL);
+    ({ workers } = yield listWorkers(tabClient));
+    let [, workerClient2] = yield attachWorker(tabClient,
+                                               findWorker(workers, WORKER2_URL));
+    is(workerClient2.isFrozen, false);
+
+    executeSoon(() => {
+      tab.linkedBrowser.contentWindow.history.back();
+    });
+    yield Promise.all([
+      waitForWorkerFreeze(workerClient2),
+      waitForWorkerThaw(workerClient1)
+    ]);
+
+    terminateWorkerInTab(tab, WORKER1_URL);
+    yield waitForWorkerClose(workerClient1);
+
+    yield close(client);
+    SpecialPowers.setIntPref(MAX_TOTAL_VIEWERS, oldMaxTotalViewers);
+    finish();
+  });
+}
diff --git a/browser/devtools/debugger/test/code_WorkerActor.attach-worker1.js b/browser/devtools/debugger/test/code_WorkerActor.attach-worker1.js
new file mode 100644
index 000000000000..18f14864d6cf
--- /dev/null
+++ b/browser/devtools/debugger/test/code_WorkerActor.attach-worker1.js
@@ -0,0 +1,5 @@
+"use strict";
+
+self.onmessage = function () {};
+
+postMessage("load");
diff --git a/browser/devtools/debugger/test/code_WorkerActor.attach-worker2.js b/browser/devtools/debugger/test/code_WorkerActor.attach-worker2.js
new file mode 100644
index 000000000000..18f14864d6cf
--- /dev/null
+++ b/browser/devtools/debugger/test/code_WorkerActor.attach-worker2.js
@@ -0,0 +1,5 @@
+"use strict";
+
+self.onmessage = function () {};
+
+postMessage("load");
diff --git a/browser/devtools/debugger/test/code_frame-script.js b/browser/devtools/debugger/test/code_frame-script.js
index c42803b10dfd..0fdb4ac674fe 100644
--- a/browser/devtools/debugger/test/code_frame-script.js
+++ b/browser/devtools/debugger/test/code_frame-script.js
@@ -13,8 +13,14 @@ addMessageListener("test:call", function (message) {
   dump("Calling function with name " + message.data.name + ".\n");
 
   let data = message.data;
-  XPCNativeWrapper.unwrap(content)[data.name].apply(undefined, data.args);
-  sendAsyncMessage("test:call");
+  let result = XPCNativeWrapper.unwrap(content)[data.name].apply(undefined, data.args);
+  if (result && result.then) {
+    result.then(() => {
+      sendAsyncMessage("test:call");
+    });
+  } else {
+    sendAsyncMessage("test:call");
+  }
 });
 
 addMessageListener("test:click", function (message) {
@@ -28,6 +34,34 @@ addMessageListener("test:click", function (message) {
 addMessageListener("test:eval", function (message) {
   dump("Evalling string " + message.data.string + ".\n");
 
-  content.eval(message.data.string);
-  sendAsyncMessage("test:eval");
+  let result = content.eval(message.data.string);
+  if (result.then) {
+    result.then(() => {
+      sendAsyncMessage("test:eval");
+    });
+  } else {
+    sendAsyncMessage("test:eval");
+  }
+});
+
+let workers = {}
+
+addMessageListener("test:createWorker", function (message) {
+  dump("Creating worker with url '" + message.data.url + "'.\n");
+
+  let url = message.data.url;
+  let worker = new content.Worker(message.data.url);
+  worker.addEventListener("message", function listener() {
+    worker.removeEventListener("message", listener);
+    sendAsyncMessage("test:createWorker");
+  });
+  workers[url] = worker;
+});
+
+addMessageListener("test:terminateWorker", function (message) {
+  dump("Terminating worker with url '" + message.data.url + "'.\n");
+
+  let url = message.data.url;
+  workers[url].terminate();
+  delete workers[url];
 });
diff --git a/browser/devtools/debugger/test/code_workeractor-worker.js b/browser/devtools/debugger/test/code_workeractor-worker.js
new file mode 100644
index 000000000000..18f14864d6cf
--- /dev/null
+++ b/browser/devtools/debugger/test/code_workeractor-worker.js
@@ -0,0 +1,5 @@
+"use strict";
+
+self.onmessage = function () {};
+
+postMessage("load");
diff --git a/browser/devtools/debugger/test/doc_WorkerActor.attach-tab1.html b/browser/devtools/debugger/test/doc_WorkerActor.attach-tab1.html
new file mode 100644
index 000000000000..62ab9be7d2e8
--- /dev/null
+++ b/browser/devtools/debugger/test/doc_WorkerActor.attach-tab1.html
@@ -0,0 +1,8 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8"/>
+  </head>
+  <body>
+  </body>
+</html>
diff --git a/browser/devtools/debugger/test/doc_WorkerActor.attach-tab2.html b/browser/devtools/debugger/test/doc_WorkerActor.attach-tab2.html
new file mode 100644
index 000000000000..62ab9be7d2e8
--- /dev/null
+++ b/browser/devtools/debugger/test/doc_WorkerActor.attach-tab2.html
@@ -0,0 +1,8 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8"/>
+  </head>
+  <body>
+  </body>
+</html>
diff --git a/browser/devtools/debugger/test/head.js b/browser/devtools/debugger/test/head.js
index 643d349414cb..ecee083d2193 100644
--- a/browser/devtools/debugger/test/head.js
+++ b/browser/devtools/debugger/test/head.js
@@ -984,7 +984,7 @@ function callInTab(tab, name) {
     name: name,
     args: Array.prototype.slice.call(arguments, 2)
   });
-  waitForMessageFromTab(tab, "test:call");
+  return waitForMessageFromTab(tab, "test:call");
 }
 
 function evalInTab(tab, string) {
@@ -993,7 +993,7 @@ function evalInTab(tab, string) {
   sendMessageToTab(tab, "test:eval", {
     string: string,
   });
-  waitForMessageFromTab(tab, "test:eval");
+  return waitForMessageFromTab(tab, "test:eval");
 }
 
 function sendMouseClickToTab(tab, target) {
@@ -1026,6 +1026,24 @@ function getSourceForm(aSources, aURL) {
   return item.attachment.source;
 }
 
+function createWorkerInTab(tab, url) {
+  info("Creating worker with url '" + url + "' in tab.");
+
+  sendMessageToTab(tab, "test:createWorker", {
+    url: url
+  });
+  return waitForMessageFromTab(tab, "test:createWorker");
+}
+
+function terminateWorkerInTab(tab, url) {
+  info("Terminating worker with url '" + url + "' in tab.");
+
+  sendMessageToTab(tab, "test:terminateWorker", {
+    url: url
+  });
+  return waitForMessageFromTab(tab, "test:terminateWorker");
+}
+
 function connect(client) {
   info("Connecting client.");
   return new Promise(function (resolve) {
@@ -1081,6 +1099,25 @@ function listWorkers(tabClient) {
   });
 }
 
+function findWorker(workers, url) {
+  info("Finding worker with url '" + url + "'.");
+  for (let worker of workers) {
+    if (worker.url === url) {
+      return worker;
+    }
+  }
+  return null;
+}
+
+function attachWorker(tabClient, worker) {
+  info("Attaching to worker with url '" + worker.url + "'.");
+  return new Promise(function(resolve, reject) {
+    tabClient.attachWorker(worker.actor, function (response, workerClient) {
+      resolve([response, workerClient]);
+    });
+  });
+}
+
 function waitForWorkerListChanged(tabClient) {
   info("Waiting for worker list to change.");
   return new Promise(function (resolve) {
@@ -1090,3 +1127,31 @@ function waitForWorkerListChanged(tabClient) {
     });
   });
 }
+
+function waitForWorkerClose(workerClient) {
+  info("Waiting for worker to close.");
+  return new Promise(function (resolve) {
+    workerClient.addOneTimeListener("close", function () {
+      info("Worker did close.");
+      resolve();
+    });
+  });
+}
+
+function waitForWorkerFreeze(workerClient) {
+  info("Waiting for worker to freeze.");
+  return new Promise(function (resolve) {
+    workerClient.addOneTimeListener("freeze", function () {
+      resolve();
+    });
+  });
+}
+
+function waitForWorkerThaw(workerClient) {
+  info("Waiting for worker to thaw.");
+  return new Promise(function (resolve) {
+    workerClient.addOneTimeListener("thaw", function () {
+      resolve();
+    });
+  });
+}
diff --git a/toolkit/components/telemetry/Histograms.json b/toolkit/components/telemetry/Histograms.json
index a0d7415142b9..62a8dacb4b8a 100644
--- a/toolkit/components/telemetry/Histograms.json
+++ b/toolkit/components/telemetry/Histograms.json
@@ -5541,6 +5541,20 @@
     "n_buckets": "1000",
     "description": "The time (in milliseconds) that it took a 'detach' request to go round trip."
   },
+  "DEVTOOLS_DEBUGGER_RDP_LOCAL_WORKERDETACH_MS": {
+    "expires_in_version": "never",
+    "kind": "exponential",
+    "high": "10000",
+    "n_buckets": "1000",
+    "description": "The time (in milliseconds) that it took a 'detach' request to go round trip."
+  },
+  "DEVTOOLS_DEBUGGER_RDP_REMOTE_WORKERDETACH_MS": {
+    "expires_in_version": "never",
+    "kind": "exponential",
+    "high": "10000",
+    "n_buckets": "1000",
+    "description": "The time (in milliseconds) that it took a 'detach' request to go round trip."
+  },
   "DEVTOOLS_DEBUGGER_DISPLAY_SOURCE_LOCAL_MS": {
     "expires_in_version": "never",
     "kind": "exponential",
diff --git a/toolkit/devtools/client/dbg-client.jsm b/toolkit/devtools/client/dbg-client.jsm
index 4d6d6b404812..43ebf59d3b74 100644
--- a/toolkit/devtools/client/dbg-client.jsm
+++ b/toolkit/devtools/client/dbg-client.jsm
@@ -51,6 +51,7 @@ Object.defineProperty(this, "WebConsoleClient", {
 });
 
 Components.utils.import("resource://gre/modules/devtools/DevToolsUtils.jsm");
+this.executeSoon = DevToolsUtils.executeSoon;
 this.makeInfallible = DevToolsUtils.makeInfallible;
 this.values = DevToolsUtils.values;
 
@@ -505,6 +506,29 @@ DebuggerClient.prototype = {
     });
   },
 
+  attachWorker: function DC_attachWorker(aWorkerActor, aOnResponse = noop) {
+    let workerClient = this._clients.get(aWorkerActor);
+    if (workerClient !== undefined) {
+      executeSoon(() => aOnResponse({
+        from: workerClient.actor,
+        type: "attached",
+        isFrozen: workerClient.isFrozen
+      }, workerClient));
+      return;
+    }
+
+    this.request({ to: aWorkerActor, type: "attach" }, (aResponse) => {
+      if (aResponse.error) {
+        aOnResponse(aResponse, null);
+        return;
+      }
+
+      let workerClient = new WorkerClient(this, aResponse);
+      this.registerClient(workerClient);
+      aOnResponse(aResponse, workerClient);
+    });
+  },
+
   /**
    * Attach to an addon actor.
    *
@@ -1326,11 +1350,82 @@ TabClient.prototype = {
     type: "listWorkers"
   }, {
     telemetry: "LISTWORKERS"
-  })
+  }),
+
+  attachWorker: function (aWorkerActor, aOnResponse) {
+    this.client.attachWorker(aWorkerActor, aOnResponse);
+  }
 };
 
 eventSource(TabClient.prototype);
 
+function WorkerClient(aClient, aForm) {
+  this._client = aClient;
+  this._actor = aForm.from;
+  this._isClosed = false;
+  this._isFrozen = aForm.isFrozen;
+
+  this._onClose = this._onClose.bind(this);
+  this._onFreeze = this._onFreeze.bind(this);
+  this._onThaw = this._onThaw.bind(this);
+
+  this.addListener("close", this._onClose);
+  this.addListener("freeze", this._onFreeze);
+  this.addListener("thaw", this._onThaw);
+}
+
+WorkerClient.prototype = {
+  get _transport() {
+    return this._client._transport;
+  },
+
+  get request() {
+    return this._client.request;
+  },
+
+  get actor() {
+    return this._actor;
+  },
+
+  get isClosed() {
+    return this._isClosed;
+  },
+
+  get isFrozen() {
+    return this._isFrozen;
+  },
+
+  detach: DebuggerClient.requester({ type: "detach" }, {
+    after: function (aResponse) {
+      this._client.unregisterClient(this);
+      return aResponse;
+    },
+
+    telemetry: "WORKERDETACH"
+  }),
+
+  _onClose: function () {
+    this.removeListener("close", this._onClose);
+    this.removeListener("freeze", this._onFreeze);
+    this.removeListener("thaw", this._onThaw);
+
+    this._client.unregisterClient(this);
+    this._closed = true;
+  },
+
+  _onFreeze: function () {
+    this._isFrozen = true;
+  },
+
+  _onThaw: function () {
+    this._isFrozen = false;
+  },
+
+  events: ["close", "freeze", "thaw"]
+};
+
+eventSource(WorkerClient.prototype);
+
 function AddonClient(aClient, aActor) {
   this._client = aClient;
   this._actor = aActor;
diff --git a/toolkit/devtools/server/actors/worker.js b/toolkit/devtools/server/actors/worker.js
index eb5f990e12f5..8f87fc79c721 100644
--- a/toolkit/devtools/server/actors/worker.js
+++ b/toolkit/devtools/server/actors/worker.js
@@ -27,6 +27,7 @@ function matchWorkerDebugger(dbg, options) {
 
 function WorkerActor(dbg) {
   this._dbg = dbg;
+  this._isAttached = false;
 }
 
 WorkerActor.prototype = {
@@ -37,9 +38,61 @@ WorkerActor.prototype = {
       actor: this.actorID,
       url: this._dbg.url
     };
+  },
+
+  onAttach: function () {
+    if (this._dbg.isClosed) {
+      return { error: "closed" };
+    }
+
+    if (!this._isAttached) {
+      this._dbg.addListener(this);
+      this._isAttached = true;
+    }
+
+    return {
+      type: "attached",
+      isFrozen: this._dbg.isFrozen
+    };
+  },
+
+  onDetach: function () {
+    if (!this._isAttached) {
+      return { error: "wrongState" };
+    }
+
+    this._detach();
+
+    return { type: "detached" };
+  },
+
+  onClose: function () {
+    if (this._isAttached) {
+      this._detach();
+    }
+
+    this.conn.sendActorEvent(this.actorID, "close");
+  },
+
+  onFreeze: function () {
+    this.conn.sendActorEvent(this.actorID, "freeze");
+  },
+
+  onThaw: function () {
+    this.conn.sendActorEvent(this.actorID, "thaw");
+  },
+
+  _detach: function () {
+    this._dbg.removeListener(this);
+    this._isAttached = false;
   }
 };
 
+WorkerActor.prototype.requestTypes = {
+  "attach": WorkerActor.prototype.onAttach,
+  "detach": WorkerActor.prototype.onDetach
+};
+
 exports.WorkerActor = WorkerActor;
 
 function WorkerActorList(options) {