diff --git a/devtools/client/application/initializer.js b/devtools/client/application/initializer.js
index 96e9a47321fc..0e0bfe9788a2 100644
--- a/devtools/client/application/initializer.js
+++ b/devtools/client/application/initializer.js
@@ -28,7 +28,7 @@ const actions = require("./src/actions/index");
 
 const { WorkersListener } = require("devtools/client/shared/workers-listener");
 
-const { services } = require("./src/modules/application-services");
+const { services } = require("./src/modules/services");
 
 const App = createFactory(require("./src/components/App"));
 
@@ -49,6 +49,7 @@ window.Application = {
 
     this.store = configureStore();
     this.actions = bindActionCreators(actions, this.store.dispatch);
+    this.serviceWorkerRegistrationFronts = [];
 
     services.init(this.toolbox);
 
@@ -103,9 +104,7 @@ window.Application = {
       ? (await this.deviceFront.getDescription()).canDebugServiceWorkers
       : false;
 
-    this.actions.updateCanDebugWorkers(
-      canDebugWorkers && services.features.doesDebuggerSupportWorkers
-    );
+    this.actions.updateCanDebugWorkers(canDebugWorkers);
   },
 
   destroy() {
diff --git a/devtools/client/application/src/actions/manifest.js b/devtools/client/application/src/actions/manifest.js
index 3ae3d5396d53..0ff90c3b028e 100644
--- a/devtools/client/application/src/actions/manifest.js
+++ b/devtools/client/application/src/actions/manifest.js
@@ -6,10 +6,7 @@
 
 const { l10n } = require("../modules/l10n");
 
-const {
-  services,
-  ManifestDevToolsError,
-} = require("../modules/application-services");
+const { services, ManifestDevToolsError } = require("../modules/services");
 const {
   FETCH_MANIFEST_FAILURE,
   FETCH_MANIFEST_START,
diff --git a/devtools/client/application/src/components/service-workers/Worker.js b/devtools/client/application/src/components/service-workers/Worker.js
index 3760f320e197..f99205028d62 100644
--- a/devtools/client/application/src/components/service-workers/Worker.js
+++ b/devtools/client/application/src/components/service-workers/Worker.js
@@ -31,11 +31,17 @@ const {
 const FluentReact = require("devtools/client/shared/vendor/fluent-react");
 const Localized = createFactory(FluentReact.Localized);
 
-const { services } = require("../../modules/application-services");
 const Types = require("../../types/index");
 
 const UIButton = createFactory(require("../ui/UIButton"));
 
+loader.lazyRequireGetter(
+  this,
+  "gDevToolsBrowser",
+  "devtools/client/framework/devtools-browser",
+  true
+);
+
 /**
  * This component is dedicated to display a worker, more accurately a service worker, in
  * the list of workers displayed in the application panel. It displays information about
@@ -64,7 +70,8 @@ class Worker extends PureComponent {
       return;
     }
 
-    services.openWorkerInDebugger(this.props.worker.workerTargetFront);
+    const { workerTargetFront } = this.props.worker;
+    gDevToolsBrowser.openWorkerToolbox(workerTargetFront);
   }
 
   start() {
diff --git a/devtools/client/application/src/components/service-workers/WorkerListEmpty.js b/devtools/client/application/src/components/service-workers/WorkerListEmpty.js
index 648c769bbb49..da39ce71f863 100644
--- a/devtools/client/application/src/components/service-workers/WorkerListEmpty.js
+++ b/devtools/client/application/src/components/service-workers/WorkerListEmpty.js
@@ -21,7 +21,7 @@ const {
 const FluentReact = require("devtools/client/shared/vendor/fluent-react");
 const Localized = createFactory(FluentReact.Localized);
 
-const { services } = require("../../modules/application-services");
+const { services } = require("../../modules/services");
 
 const DOC_URL =
   "https://developer.mozilla.org/docs/Web/API/Service_Worker_API/Using_Service_Workers" +
diff --git a/devtools/client/application/src/modules/moz.build b/devtools/client/application/src/modules/moz.build
index af4edb800952..f4b8f4cb1146 100644
--- a/devtools/client/application/src/modules/moz.build
+++ b/devtools/client/application/src/modules/moz.build
@@ -3,6 +3,6 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DevToolsModules(
-    'application-services.js',
     'l10n.js',
+    'services.js',
 )
diff --git a/devtools/client/application/src/modules/application-services.js b/devtools/client/application/src/modules/services.js
similarity index 73%
rename from devtools/client/application/src/modules/application-services.js
rename to devtools/client/application/src/modules/services.js
index 0931ddf7bf18..f4cf050f5059 100644
--- a/devtools/client/application/src/modules/application-services.js
+++ b/devtools/client/application/src/modules/services.js
@@ -4,8 +4,6 @@
 
 "use strict";
 
-const Services = require("Services");
-
 class ManifestDevToolsError extends Error {
   constructor(...params) {
     super(...params);
@@ -14,16 +12,9 @@ class ManifestDevToolsError extends Error {
   }
 }
 
-class ApplicationServices {
+class Services {
   init(toolbox) {
     this._toolbox = toolbox;
-
-    this.features = {
-      doesDebuggerSupportWorkers: Services.prefs.getBoolPref(
-        "devtools.debugger.features.windowless-service-workers",
-        false
-      ),
-    };
   }
 
   selectTool(toolId) {
@@ -31,11 +22,6 @@ class ApplicationServices {
     return this._toolbox.selectTool(toolId);
   }
 
-  async openWorkerInDebugger(workerTargetFront) {
-    const debuggerPanel = await this.selectTool("jsdebugger");
-    debuggerPanel.selectWorker(workerTargetFront);
-  }
-
   async fetchManifest() {
     let response;
 
@@ -68,5 +54,5 @@ class ApplicationServices {
 module.exports = {
   ManifestDevToolsError,
   // exports a singleton, which will be used across all application panel modules
-  services: new ApplicationServices(),
+  services: new Services(),
 };
diff --git a/devtools/client/application/test/browser/browser.ini b/devtools/client/application/test/browser/browser.ini
index 526b9629571a..2c5fc2930408 100644
--- a/devtools/client/application/test/browser/browser.ini
+++ b/devtools/client/application/test/browser/browser.ini
@@ -30,7 +30,7 @@ support-files =
 [browser_application_panel_debug-service-worker.js]
 skip-if = debug || asan # Bug 1559591, 1575578
 [browser_application_panel_disable-start-service-worker.js]
-skip-if = (os == 'linux' && asan) || debug # Bug 1559487, 1559591
+skip-if = (os == 'linux' && asan) || debug || serviceworker_e10s # Bug 1559487, 1559591, 1447197
 [browser_application_panel_list-domain-workers.js]
 skip-if = debug # Bug 1559591
 [browser_application_panel_list-several-workers.js]
@@ -49,4 +49,4 @@ skip-if = true # Bug 1467256, 1559591
 [browser_application_panel_unregister-worker.js]
 skip-if = debug # Bug 1559591
 [browser_application_panel_start-service-worker.js]
-skip-if = (os == 'linux' && asan) || debug # Bug 1559487, 1559591
+skip-if = (os == 'linux' && asan) || debug # Bug 1559487, 1559591, 1447197
diff --git a/devtools/client/application/test/browser/browser_application_panel_debug-service-worker.js b/devtools/client/application/test/browser/browser_application_panel_debug-service-worker.js
index 05fa62042aad..1e13e0ce9a53 100644
--- a/devtools/client/application/test/browser/browser_application_panel_debug-service-worker.js
+++ b/devtools/client/application/test/browser/browser_application_panel_debug-service-worker.js
@@ -20,10 +20,7 @@ const TAB_URL = URL_ROOT + "resources/service-workers/debug.html";
 add_task(async function() {
   await enableApplicationPanel();
 
-  const { panel, tab, target, toolbox } = await openNewTabAndApplicationPanel(
-    TAB_URL
-  );
-
+  const { panel, tab, target } = await openNewTabAndApplicationPanel(TAB_URL);
   const doc = panel.panelWin.document;
 
   selectPage(panel, "service-workers");
@@ -38,28 +35,39 @@ add_task(async function() {
     return button && !button.disabled;
   });
 
-  info("Click on the debug button and wait for debugger to be ready");
+  info("Click on the debug button and wait for the new toolbox to be ready");
+  const onToolboxReady = gDevTools.once("toolbox-ready");
+
   const debugButton = container.querySelector(".js-debug-button");
   debugButton.click();
-  await waitFor(() => toolbox.getPanel("jsdebugger"));
 
-  // add a breakpoint at line 11
-  const debuggerContext = createDebuggerContext(toolbox);
+  const serviceWorkerToolbox = await onToolboxReady;
+  await serviceWorkerToolbox.selectTool("jsdebugger");
+  const debuggerContext = createDebuggerContext(serviceWorkerToolbox);
+
+  await waitForSources(debuggerContext, "debug-sw.js");
+  await selectSource(debuggerContext, "debug-sw.js");
   await waitForLoadedSource(debuggerContext, "debug-sw.js");
-  await addBreakpoint(debuggerContext, "debug-sw.js", 11);
 
-  // force a pause at the breakpoint
-  info("Invoke fetch, expect the service worker script to pause on line 11");
-  await ContentTask.spawn(tab.linkedBrowser, {}, async function() {
-    content.wrappedJSObject.fetchFromWorker();
-  });
+  await addBreakpoint(debuggerContext, "debug-sw.js", 8);
+
+  info(
+    "Reload the main tab, expect the service worker script to pause on line 8"
+  );
+  tab.linkedBrowser.reload();
+
   await waitForPaused(debuggerContext);
   assertPausedLocation(debuggerContext);
   await resume(debuggerContext);
 
-  // remove breakpoint
   const workerScript = findSource(debuggerContext, "debug-sw.js");
-  await removeBreakpoint(debuggerContext, workerScript.id, 11);
+  await removeBreakpoint(debuggerContext, workerScript.id, 8);
+
+  info("Destroy the worker toolbox");
+  await serviceWorkerToolbox.destroy();
+
+  info("Wait until the focus goes back to the main window");
+  await waitUntil(() => gBrowser.selectedBrowser === tab.linkedBrowser);
 
   await unregisterAllWorkers(target.client);
 });
diff --git a/devtools/client/application/test/browser/browser_application_panel_disable-start-service-worker.js b/devtools/client/application/test/browser/browser_application_panel_disable-start-service-worker.js
index d8ee16ab76ce..a9c51a2be679 100644
--- a/devtools/client/application/test/browser/browser_application_panel_disable-start-service-worker.js
+++ b/devtools/client/application/test/browser/browser_application_panel_disable-start-service-worker.js
@@ -11,19 +11,9 @@ const TAB_URL = URL_ROOT + "resources/service-workers/simple.html";
 add_task(async function() {
   await enableApplicationPanel();
 
-  // Setting a low idle_timeout and idle_extended_timeout will allow the service worker
-  // to reach the STOPPED state quickly, which will allow us to test the start button.
-  // The default value is 30000 milliseconds.
-  info("Set a low service worker idle timeout");
-  await pushPref("dom.serviceWorkers.idle_timeout", 1000);
-  await pushPref("dom.serviceWorkers.idle_extended_timeout", 1000);
-
-  // disable sw debugging
+  // disable sw debugging by increasing the # of processes and thus multi-e10s kicking in
   info("Disable service worker debugging");
-  await pushPref(
-    "devtools.debugger.features.windowless-service-workers",
-    false
-  );
+  await pushPref("dom.ipc.processCount", 8);
 
   const { panel, tab, target } = await openNewTabAndApplicationPanel(TAB_URL);
   const doc = panel.panelWin.document;
diff --git a/devtools/client/application/test/browser/head.js b/devtools/client/application/test/browser/head.js
index 2c3f74f73af9..b0efff7ef2bb 100644
--- a/devtools/client/application/test/browser/head.js
+++ b/devtools/client/application/test/browser/head.js
@@ -25,9 +25,6 @@ async function enableServiceWorkerDebugging() {
   // SW debugging in multi-e10s.
   await pushPref("dom.ipc.processCount", 1);
 
-  // Enable service workers in the debugger
-  await pushPref("devtools.debugger.features.windowless-service-workers", true);
-
   // Wait for dom.ipc.processCount to be updated before releasing processes.
   Services.ppmm.releaseCachedProcesses();
 }
diff --git a/devtools/client/application/test/browser/resources/service-workers/debug-sw.js b/devtools/client/application/test/browser/resources/service-workers/debug-sw.js
index 7acf2545de6c..d3bb313e29f3 100644
--- a/devtools/client/application/test/browser/resources/service-workers/debug-sw.js
+++ b/devtools/client/application/test/browser/resources/service-workers/debug-sw.js
@@ -3,16 +3,8 @@
 
 "use strict";
 
-self.addEventListener("activate", event => {
-  event.waitUntil(self.clients.claim());
-});
-
+// Bug 1328293
 self.onfetch = function(event) {
-  const url = event.request.url;
-
-  const response = url.endsWith("test")
-    ? new Response("lorem ipsum", { statusText: "OK" })
-    : fetch(event.request);
-
-  event.respondWith(response);
+  const a = 5;
+  console.log(a);
 };
diff --git a/devtools/client/application/test/browser/resources/service-workers/debug.html b/devtools/client/application/test/browser/resources/service-workers/debug.html
index f0f16858fd57..da70ab66efca 100644
--- a/devtools/client/application/test/browser/resources/service-workers/debug.html
+++ b/devtools/client/application/test/browser/resources/service-workers/debug.html
@@ -11,15 +11,6 @@
 <script type="text/javascript">
 "use strict";
 window.sw = navigator.serviceWorker.register("debug-sw.js");
-
-/* exported fetchFromWorker */
-async function fetchFromWorker() {
-  const response = await fetch("test");
-  const text = await response.text();
-  console.log(`Response from worker: ${text}`);
-}
 </script>
-
-<p>This page has a <code>fetchFromWorker()</code> function.</p>
 </body>
 </html>
diff --git a/devtools/client/application/test/node/actions/actions_application_panel-manifest.test.js b/devtools/client/application/test/node/actions/actions_application_panel-manifest.test.js
index 4e6f3450676a..1dc819e9b15d 100644
--- a/devtools/client/application/test/node/actions/actions_application_panel-manifest.test.js
+++ b/devtools/client/application/test/node/actions/actions_application_panel-manifest.test.js
@@ -12,7 +12,7 @@ const { setupStore } = require("devtools/client/application/test/node/helpers");
 const {
   ManifestDevToolsError,
   services,
-} = require("devtools/client/application/src/modules/application-services");
+} = require("devtools/client/application/src/modules/services");
 
 const {
   FETCH_MANIFEST_FAILURE,
diff --git a/devtools/client/debugger/panel.js b/devtools/client/debugger/panel.js
index 702c6bcf692e..cbce63a7b837 100644
--- a/devtools/client/debugger/panel.js
+++ b/devtools/client/debugger/panel.js
@@ -9,12 +9,6 @@ loader.lazyRequireGetter(
   "devtools/client/shared/link",
   true
 );
-loader.lazyRequireGetter(
-  this,
-  "features",
-  "devtools/client/debugger/src/utils/prefs",
-  true
-);
 
 const DBG_STRINGS_URI = "devtools/client/locales/debugger.properties";
 const L10N = new LocalizationHelper(DBG_STRINGS_URI);
@@ -177,29 +171,6 @@ DebuggerPanel.prototype = {
     return this._actions.selectSourceURL(cx, url, { line, column });
   },
 
-  async selectWorker(workerTargetFront) {
-    const threadId = workerTargetFront.threadFront.actorID;
-    const isThreadAvailable = this._selectors
-      .getThreads(this._getState())
-      .find(x => x.actor === threadId);
-
-    if (!features.windowlessServiceWorkers) {
-      console.error(
-        "Selecting a worker needs the pref debugger.features.windowless-service-workers set to true"
-      );
-    } else if (!isThreadAvailable) {
-      console.error(`Worker ${threadId} is not available for debugging`);
-    } else {
-      // select worker's thread
-      const cx = this._selectors.getContext(this._getState());
-      this._actions.selectThread(cx, threadId);
-
-      // select worker's source
-      const source = this.getSourceByURL(workerTargetFront._url);
-      await this.selectSource(source.id, 1, 1);
-    }
-  },
-
   previewPausedLocation(location) {
     return this._actions.previewPausedLocation(location);
   },