diff --git a/browser/actors/WebRTCChild.jsm b/browser/actors/WebRTCChild.jsm
index dcbabc0cfac5..f2a022acdcb6 100644
--- a/browser/actors/WebRTCChild.jsm
+++ b/browser/actors/WebRTCChild.jsm
@@ -491,5 +491,5 @@ function getTabStateForContentWindow(aContentWindow, aForRemove = false) {
 }
 
 function getInnerWindowIDForWindow(aContentWindow) {
-  return aContentWindow.windowUtils.currentInnerWindowID;
+  return aContentWindow.windowGlobalChild.innerWindowId;
 }
diff --git a/browser/components/extensions/test/browser/browser_ext_getViews.js b/browser/components/extensions/test/browser/browser_ext_getViews.js
index be8c1dce5fae..a8c5183d7564 100644
--- a/browser/components/extensions/test/browser/browser_ext_getViews.js
+++ b/browser/components/extensions/test/browser/browser_ext_getViews.js
@@ -97,7 +97,7 @@ async function promiseBrowserContentUnloaded(browser) {
     browser,
     MSG_WINDOW_DESTROYED,
     MSG_WINDOW_DESTROYED => {
-      let innerWindowId = this.content.windowUtils.currentInnerWindowID;
+      let innerWindowId = this.content.windowGlobalChild.innerWindowId;
       let observer = subject => {
         if (
           innerWindowId === subject.QueryInterface(Ci.nsISupportsPRUint64).data
diff --git a/browser/extensions/report-site-issue/experimentalAPIs/actors/tabExtrasActor.jsm b/browser/extensions/report-site-issue/experimentalAPIs/actors/tabExtrasActor.jsm
index b79b60ea830a..869856dbeab9 100644
--- a/browser/extensions/report-site-issue/experimentalAPIs/actors/tabExtrasActor.jsm
+++ b/browser/extensions/report-site-issue/experimentalAPIs/actors/tabExtrasActor.jsm
@@ -135,7 +135,7 @@ class ReportSiteIssueHelperChild extends JSWindowActorChild {
   }
 
   _getLoggedMessages(includePrivate = false) {
-    const windowId = this.contentWindow.windowUtils.currentInnerWindowID;
+    const windowId = this.contentWindow.windowGlobalChild.innerWindowId;
     return this._getConsoleMessages(windowId).concat(
       this._getScriptErrors(windowId, includePrivate)
     );
diff --git a/caps/tests/mochitest/test_bug995943.xhtml b/caps/tests/mochitest/test_bug995943.xhtml
index 5a228155fd91..adb7701e4a9f 100644
--- a/caps/tests/mochitest/test_bug995943.xhtml
+++ b/caps/tests/mochitest/test_bug995943.xhtml
@@ -71,7 +71,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=995943
 
   var gGoCount = 0;
   function go() {
-    debug("Invoking go for window with id: " + window.windowUtils.currentInnerWindowID);
+    debug("Invoking go for window with id: " + window.windowGlobalChild.innerWindowId);
     is(++gGoCount, 1, "Should only call go once!");
     checkLoadFileURI('http://example.com', false).then(
       pushPrefs.bind(null, [['capability.policy.policynames', ' somepolicy '],
diff --git a/devtools/server/actors/addon/webextension-inspected-window.js b/devtools/server/actors/addon/webextension-inspected-window.js
index 06a8eed1d47d..e091ab7f22c9 100644
--- a/devtools/server/actors/addon/webextension-inspected-window.js
+++ b/devtools/server/actors/addon/webextension-inspected-window.js
@@ -80,7 +80,7 @@ function logAccessDeniedWarning(window, callerInfo, extensionPolicy) {
 
   const msg = `The extension "${name}" is not allowed to access ${reportedURIorPrincipal.spec}`;
 
-  const innerWindowId = window.windowUtils.currentInnerWindowID;
+  const innerWindowId = window.windowGlobalChild.innerWindowId;
 
   const errorFlag = 0;
 
diff --git a/devtools/server/actors/network-monitor/eventsource-actor.js b/devtools/server/actors/network-monitor/eventsource-actor.js
index 35ce82e7cac5..3ac12c304dc5 100644
--- a/devtools/server/actors/network-monitor/eventsource-actor.js
+++ b/devtools/server/actors/network-monitor/eventsource-actor.js
@@ -46,7 +46,7 @@ const EventSourceActor = ActorClassWithSpec(eventSourceSpec, {
 
   startListening: function() {
     this.stopListening();
-    this.innerWindowID = this.targetActor.window.windowUtils.currentInnerWindowID;
+    this.innerWindowID = this.targetActor.window.windowGlobalChild.innerWindowId;
     eventSourceEventService.addListener(this.innerWindowID, this);
   },
 
diff --git a/devtools/server/actors/network-monitor/websocket-actor.js b/devtools/server/actors/network-monitor/websocket-actor.js
index 00b3e67df065..c4a0af0685e1 100644
--- a/devtools/server/actors/network-monitor/websocket-actor.js
+++ b/devtools/server/actors/network-monitor/websocket-actor.js
@@ -50,7 +50,7 @@ const WebSocketActor = ActorClassWithSpec(webSocketSpec, {
 
   startListening: function() {
     this.stopListening();
-    this.innerWindowID = this.targetActor.window.windowUtils.currentInnerWindowID;
+    this.innerWindowID = this.targetActor.window.windowGlobalChild.innerWindowId;
     webSocketEventService.addListener(this.innerWindowID, this);
   },
 
diff --git a/devtools/server/actors/storage.js b/devtools/server/actors/storage.js
index 61150d66f175..874b34ad2bd8 100644
--- a/devtools/server/actors/storage.js
+++ b/devtools/server/actors/storage.js
@@ -3542,7 +3542,7 @@ const StorageActor = protocol.ActorClassWithSpec(specs.storageSpec, {
   getWindowFromInnerWindowID(innerID) {
     innerID = innerID.QueryInterface(Ci.nsISupportsPRUint64).data;
     for (const win of this.childWindowPool.values()) {
-      const id = win.windowUtils.currentInnerWindowID;
+      const id = win.windowGlobalChild.innerWindowId;
       if (id == innerID) {
         return win;
       }
diff --git a/devtools/server/actors/targets/browsing-context.js b/devtools/server/actors/targets/browsing-context.js
index 3229b01faaff..3d57b76b638c 100644
--- a/devtools/server/actors/targets/browsing-context.js
+++ b/devtools/server/actors/targets/browsing-context.js
@@ -72,7 +72,7 @@ loader.lazyRequireGetter(
 );
 
 function getWindowID(window) {
-  return window.windowUtils.currentInnerWindowID;
+  return window.windowGlobalChild.innerWindowId;
 }
 
 function getDocShellChromeEventHandler(docShell) {
@@ -112,7 +112,7 @@ exports.getChildDocShells = getChildDocShells;
  */
 
 function getInnerId(window) {
-  return window.windowUtils.currentInnerWindowID;
+  return window.windowGlobalChild.innerWindowId;
 }
 
 const browsingContextTargetPrototype = {
diff --git a/devtools/server/actors/webconsole/utils.js b/devtools/server/actors/webconsole/utils.js
index 25b2a428bea8..a35e7cf2a250 100644
--- a/devtools/server/actors/webconsole/utils.js
+++ b/devtools/server/actors/webconsole/utils.js
@@ -88,10 +88,10 @@ var WebConsoleUtils = {
    *         Inner ID for the given window, null if we can't access it.
    */
   getInnerWindowId: function(window) {
-    // Might throw with SecurityError: Permission denied to access property "windowUtils"
-    // on cross-origin object.
+    // Might throw with SecurityError: Permission denied to access property
+    // "windowGlobalChild" on cross-origin object.
     try {
-      return window.windowUtils.currentInnerWindowID;
+      return window.windowGlobalChild.innerWindowId;
     } catch (e) {
       return null;
     }
@@ -546,7 +546,7 @@ WebConsoleCommands._registerOriginal("cd", function(owner, window) {
     0,
     1,
     "content javascript",
-    owner.window.windowUtils.currentInnerWindowID
+    owner.window.windowGlobalChild.innerWindowId
   );
   const Services = require("Services");
   Services.console.logMessage(scriptError);
diff --git a/devtools/shared/content-observer.js b/devtools/shared/content-observer.js
index 30578e805d87..805037427b9e 100644
--- a/devtools/shared/content-observer.js
+++ b/devtools/shared/content-observer.js
@@ -72,5 +72,5 @@ ContentObserver.prototype = {
 // Utility functions.
 
 ContentObserver.GetInnerWindowID = function(window) {
-  return window.windowUtils.currentInnerWindowID;
+  return window.windowGlobalChild.innerWindowId;
 };
diff --git a/devtools/shared/screenshot/capture.js b/devtools/shared/screenshot/capture.js
index 6173d3465d06..eb8fc47224f6 100644
--- a/devtools/shared/screenshot/capture.js
+++ b/devtools/shared/screenshot/capture.js
@@ -201,7 +201,7 @@ function logInPage(text, flags, window) {
     0,
     flags,
     "screenshot",
-    window.windowUtils.currentInnerWindowID
+    window.windowGlobalChild.innerWindowId
   );
   Services.console.logMessage(scriptError);
 }
diff --git a/devtools/shared/webconsole/test/chrome/test_consoleapi_innerID.html b/devtools/shared/webconsole/test/chrome/test_consoleapi_innerID.html
index 0b3d70371103..19b92e1d0d3d 100644
--- a/devtools/shared/webconsole/test/chrome/test_consoleapi_innerID.html
+++ b/devtools/shared/webconsole/test/chrome/test_consoleapi_innerID.html
@@ -22,7 +22,7 @@ function doConsoleCalls(aState)
 {
   const { ConsoleAPI } = ChromeUtils.import("resource://gre/modules/Console.jsm");
   const console = new ConsoleAPI({
-    innerID: window.windowUtils.currentInnerWindowID
+    innerID: window.windowGlobalChild.innerWindowId
   });
 
   const longString = (new Array(DevToolsServer.LONG_STRING_LENGTH + 2)).join("a");
diff --git a/docshell/test/browser/browser_onbeforeunload_navigation.js b/docshell/test/browser/browser_onbeforeunload_navigation.js
index 48101c63f71b..c3e48e8714eb 100644
--- a/docshell/test/browser/browser_onbeforeunload_navigation.js
+++ b/docshell/test/browser/browser_onbeforeunload_navigation.js
@@ -123,7 +123,7 @@ add_task(async function test() {
           let { testFns } = this.content.wrappedJSObject;
           this.content.onbeforeunload = testFns[testIdx];
           this.content.location = url;
-          return this.content.windowUtils.currentInnerWindowID;
+          return this.content.windowGlobalChild.innerWindowId;
         }
       );
 
@@ -142,7 +142,7 @@ add_task(async function test() {
               "Page should have navigated to the correct URL"
             );
             Assert.notEqual(
-              this.content.windowUtils.currentInnerWindowID,
+              this.content.windowGlobalChild.innerWindowId,
               winID,
               "Page should have a new inner window"
             );
@@ -157,7 +157,7 @@ add_task(async function test() {
             "Page should have the same URL"
           );
           Assert.equal(
-            this.content.windowUtils.currentInnerWindowID,
+            this.content.windowGlobalChild.innerWindowId,
             winID,
             "Page should have the same inner window"
           );
diff --git a/dom/base/DOMRequestHelper.jsm b/dom/base/DOMRequestHelper.jsm
index d32840441f05..2b2aca05b464 100644
--- a/dom/base/DOMRequestHelper.jsm
+++ b/dom/base/DOMRequestHelper.jsm
@@ -157,8 +157,7 @@ DOMRequestIpcHelper.prototype = {
     this._window = aWindow;
     if (this._window) {
       // We don't use this.innerWindowID, but other classes rely on it.
-      let util = this._window.windowUtils;
-      this.innerWindowID = util.currentInnerWindowID;
+      this.innerWindowID = this._window.windowGlobalChild.innerWindowId;
     }
 
     this._destroyed = false;
diff --git a/dom/base/nsDOMWindowUtils.cpp b/dom/base/nsDOMWindowUtils.cpp
index 19e888a23fe4..96ecc484331a 100644
--- a/dom/base/nsDOMWindowUtils.cpp
+++ b/dom/base/nsDOMWindowUtils.cpp
@@ -2154,20 +2154,6 @@ nsDOMWindowUtils::GetOuterWindowID(uint64_t* aWindowID) {
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsDOMWindowUtils::GetCurrentInnerWindowID(uint64_t* aWindowID) {
-  nsCOMPtr<nsPIDOMWindowOuter> window = do_QueryReferent(mWindow);
-  NS_ENSURE_TRUE(window, NS_ERROR_NOT_AVAILABLE);
-
-  nsGlobalWindowInner* inner =
-      nsGlobalWindowOuter::Cast(window)->GetCurrentInnerWindowInternal();
-  if (!inner) {
-    return NS_ERROR_NOT_AVAILABLE;
-  }
-  *aWindowID = inner->WindowID();
-  return NS_OK;
-}
-
 NS_IMETHODIMP
 nsDOMWindowUtils::SuspendTimeouts() {
   nsCOMPtr<nsPIDOMWindowOuter> window = do_QueryReferent(mWindow);
diff --git a/dom/base/test/test_eventsourceservice_basic.html b/dom/base/test/test_eventsourceservice_basic.html
index 5009c48a7414..da08fb0cd94b 100644
--- a/dom/base/test/test_eventsourceservice_basic.html
+++ b/dom/base/test/test_eventsourceservice_basic.html
@@ -14,7 +14,7 @@ var service = SpecialPowers.Cc["@mozilla.org/eventsourceevent/service;1"]
                 .getService(SpecialPowers.Ci.nsIEventSourceEventService);
 ok(!!service, "We have the nsIEventSourceEventService");
 
-var innerId = SpecialPowers.getDOMWindowUtils(window).currentInnerWindowID;
+var innerId = SpecialPowers.wrap(window).windowGlobalChild.innerWindowId;
 ok(innerId, "We have a valid innerWindowID: " + innerId);
 
 var channelId = null;
@@ -66,4 +66,4 @@ SimpleTest.waitForExplicitFinish();
 </script>
 </pre>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/dom/base/test/test_eventsourceservice_reconnect_error.html b/dom/base/test/test_eventsourceservice_reconnect_error.html
index cf44ead9e7a5..cb124693c9f0 100644
--- a/dom/base/test/test_eventsourceservice_reconnect_error.html
+++ b/dom/base/test/test_eventsourceservice_reconnect_error.html
@@ -14,7 +14,7 @@ var service = SpecialPowers.Cc["@mozilla.org/eventsourceevent/service;1"]
                 .getService(SpecialPowers.Ci.nsIEventSourceEventService);
 ok(!!service, "We have the nsIEventSourceEventService");
 
-var innerId = SpecialPowers.getDOMWindowUtils(window).currentInnerWindowID;
+var innerId = SpecialPowers.wrap(window).windowGlobalChild.innerWindowId;
 ok(innerId, "We have a valid innerWindowID: " + innerId);
 
 var channelId;
@@ -69,4 +69,4 @@ function checkCallsCount() {
 </script>
 </pre>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/dom/base/test/test_eventsourceservice_status_error.html b/dom/base/test/test_eventsourceservice_status_error.html
index 637af8eb8351..55be8e0dc79a 100644
--- a/dom/base/test/test_eventsourceservice_status_error.html
+++ b/dom/base/test/test_eventsourceservice_status_error.html
@@ -14,7 +14,7 @@ var service = SpecialPowers.Cc["@mozilla.org/eventsourceevent/service;1"]
                 .getService(SpecialPowers.Ci.nsIEventSourceEventService);
 ok(!!service, "We have the nsIEventSourceEventService");
 
-var innerId = SpecialPowers.getDOMWindowUtils(window).currentInnerWindowID;
+var innerId = SpecialPowers.wrap(window).windowGlobalChild.innerWindowId;
 ok(innerId, "We have a valid innerWindowID: " + innerId);
 
 var listener = {
@@ -64,4 +64,4 @@ function doTest(status) {
 </script>
 </pre>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/dom/base/test/test_eventsourceservice_worker.html b/dom/base/test/test_eventsourceservice_worker.html
index d71d29ce0798..99c89f4e5085 100644
--- a/dom/base/test/test_eventsourceservice_worker.html
+++ b/dom/base/test/test_eventsourceservice_worker.html
@@ -14,7 +14,7 @@ var service = SpecialPowers.Cc["@mozilla.org/eventsourceevent/service;1"]
                 .getService(SpecialPowers.Ci.nsIEventSourceEventService);
 ok(!!service, "We have the nsIEventSourceEventService");
 
-var innerId = SpecialPowers.getDOMWindowUtils(window).currentInnerWindowID;
+var innerId = SpecialPowers.wrap(window).windowGlobalChild.innerWindowId;
 ok(innerId, "We have a valid innerWindowID: " + innerId);
 
 var channelId = null;
@@ -58,4 +58,4 @@ SimpleTest.waitForExplicitFinish();
 </script>
 </pre>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/dom/browser-element/BrowserElementChildPreload.js b/dom/browser-element/BrowserElementChildPreload.js
index bc6cc1d9bb57..8cf7bb1b5ba0 100644
--- a/dom/browser-element/BrowserElementChildPreload.js
+++ b/dom/browser-element/BrowserElementChildPreload.js
@@ -134,9 +134,8 @@ BrowserElementChild.prototype = {
   },
 
   _tryGetInnerWindowID(win) {
-    let utils = win.windowUtils;
     try {
-      return utils.currentInnerWindowID;
+      return win.windowGlobalChild.innerWindowId;
     } catch (e) {
       return null;
     }
diff --git a/dom/interfaces/base/nsIDOMWindowUtils.idl b/dom/interfaces/base/nsIDOMWindowUtils.idl
index 4fb2908efc3b..b17a4ce1fbdf 100644
--- a/dom/interfaces/base/nsIDOMWindowUtils.idl
+++ b/dom/interfaces/base/nsIDOMWindowUtils.idl
@@ -1303,12 +1303,6 @@ interface nsIDOMWindowUtils : nsISupports {
    */
   readonly attribute unsigned long long outerWindowID;
 
-  /**
-   * Get the id of the current inner window of this window.  If there
-   * is no current inner window, throws NS_ERROR_NOT_AVAILABLE.
-   */
-  readonly attribute unsigned long long currentInnerWindowID;
-
   /**
    * Put the window into a state where scripts are frozen and events
    * suppressed, for use when the window has launched a modal prompt.
diff --git a/dom/media/IdpSandbox.jsm b/dom/media/IdpSandbox.jsm
index a4733f91cd35..b407a14ee025 100644
--- a/dom/media/IdpSandbox.jsm
+++ b/dom/media/IdpSandbox.jsm
@@ -257,7 +257,7 @@ IdpSandbox.prototype = {
   // can't rethrow anything else because that could leak information about the
   // internal workings of the IdP across origins.
   _logError(e) {
-    let winID = this.window.windowUtils.currentInnerWindowID;
+    let winID = this.window.windowGlobalChild.innerWindowId;
     let scriptError = Cc["@mozilla.org/scripterror;1"].createInstance(
       Ci.nsIScriptError
     );
diff --git a/dom/media/PeerConnection.jsm b/dom/media/PeerConnection.jsm
index ff36fdbeec8e..5d02f70e27a9 100644
--- a/dom/media/PeerConnection.jsm
+++ b/dom/media/PeerConnection.jsm
@@ -253,7 +253,7 @@ setupPrototype(RTCIceCandidate, {
 class RTCSessionDescription {
   init(win) {
     this._win = win;
-    this._winID = this._win.windowUtils.currentInnerWindowID;
+    this._winID = this._win.windowGlobalChild.innerWindowId;
   }
 
   __init({ type, sdp }) {
@@ -389,7 +389,7 @@ class RTCPeerConnection {
   }
 
   __init(rtcConfig) {
-    this._winID = this._win.windowUtils.currentInnerWindowID;
+    this._winID = this._win.windowGlobalChild.innerWindowId;
     // TODO: Update this code once we support pc.setConfiguration, to track
     // setting from content independently from pref (Bug 1181768).
     if (
@@ -2020,7 +2020,7 @@ setupPrototype(PeerConnectionObserver, {
 
 class RTCPeerConnectionStatic {
   init(win) {
-    this._winID = win.windowUtils.currentInnerWindowID;
+    this._winID = win.windowGlobalChild.innerWindowId;
   }
 
   registerPeerConnectionLifecycleCallback(cb) {
diff --git a/dom/push/test/test_utils.js b/dom/push/test/test_utils.js
index 73d49cc0d642..b704f17138aa 100644
--- a/dom/push/test/test_utils.js
+++ b/dom/push/test/test_utils.js
@@ -216,8 +216,8 @@ function injectControlledFrame(target = document.body) {
           : Promise.reject(new Error("Frame removed from document"));
       },
       innerWindowId() {
-        var utils = SpecialPowers.getDOMWindowUtils(iframe.contentWindow);
-        return utils.currentInnerWindowID;
+        return SpecialPowers.wrap(iframe).browsingContext.currentWindowContext
+          .innerWindowId;
       },
     };
 
diff --git a/dom/tests/browser/browser_ConsoleStorageAPITests.js b/dom/tests/browser/browser_ConsoleStorageAPITests.js
index 39b12d13ba12..4322d61c480c 100644
--- a/dom/tests/browser/browser_ConsoleStorageAPITests.js
+++ b/dom/tests/browser/browser_ConsoleStorageAPITests.js
@@ -40,7 +40,7 @@ add_task(async function() {
           if (aTopic == "console-storage-cache-event") {
             apiCallCount++;
             if (apiCallCount == 4) {
-              let windowId = content.window.windowUtils.currentInnerWindowID;
+              let windowId = content.windowGlobalChild.innerWindowId;
 
               Services.obs.removeObserver(this, "console-storage-cache-event");
               ok(
diff --git a/dom/tests/browser/browser_ConsoleStoragePBTest_perwindowpb.js b/dom/tests/browser/browser_ConsoleStoragePBTest_perwindowpb.js
index 0ce1d4ad7587..1c61a7fbcc36 100644
--- a/dom/tests/browser/browser_ConsoleStoragePBTest_perwindowpb.js
+++ b/dom/tests/browser/browser_ConsoleStoragePBTest_perwindowpb.js
@@ -17,7 +17,7 @@ function test() {
   );
 
   function getInnerWindowId(aWindow) {
-    return aWindow.windowUtils.currentInnerWindowID;
+    return aWindow.windowGlobalChild.innerWindowId;
   }
 
   function whenNewWindowLoaded(aOptions, aCallback) {
diff --git a/dom/tests/browser/file_postMessage_parent.html b/dom/tests/browser/file_postMessage_parent.html
index 910ad9183c38..f9aa63a8c7c1 100644
--- a/dom/tests/browser/file_postMessage_parent.html
+++ b/dom/tests/browser/file_postMessage_parent.html
@@ -2,7 +2,7 @@
 <script>
   dump("Content running top level script " + window.location.href + "\n");
 
-  var winID = SpecialPowers.getDOMWindowUtils(this).currentInnerWindowID;
+  var winID = SpecialPowers.wrap(this).windowGlobalChild.innerWindowId;
 
   var observer = {
     observe(subject, topic) {
diff --git a/dom/tests/mochitest/bugs/test_bug534149.html b/dom/tests/mochitest/bugs/test_bug534149.html
index 55e7e4882b90..2d8180e79901 100644
--- a/dom/tests/mochitest/bugs/test_bug534149.html
+++ b/dom/tests/mochitest/bugs/test_bug534149.html
@@ -23,8 +23,10 @@ function getIDs(iframe) {
   // Force inner creation
   win.document;
 
-  var util = SpecialPowers.getDOMWindowUtils(win);
-  return [util.outerWindowID, util.currentInnerWindowID];
+  return [
+    SpecialPowers.getDOMWindowUtils(win).outerWindowID,
+    SpecialPowers.wrap(win).windowGlobalChild.innerWindowId,
+  ];
 }
 
 var i1 = document.createElement("iframe");
diff --git a/dom/websocket/tests/test_websocket_frame.html b/dom/websocket/tests/test_websocket_frame.html
index 32cd98ff1c2f..26910246e4c5 100644
--- a/dom/websocket/tests/test_websocket_frame.html
+++ b/dom/websocket/tests/test_websocket_frame.html
@@ -26,7 +26,7 @@ var tests = [
   { payload: (function() { var buffer = ""; for (var i = 0; i < 120; ++i) buffer += i; return buffer; }()) },
 ]
 
-var innerId = window.top.windowUtils.currentInnerWindowID;
+var innerId = window.top.windowGlobalChild.innerWindowId;
 ok(innerId, "We have a valid innerWindowID: " + innerId);
 
 var service = Cc["@mozilla.org/websocketevent/service;1"]
diff --git a/js/xpconnect/tests/chrome/test_scripterror.html b/js/xpconnect/tests/chrome/test_scripterror.html
index c3c2b70dad31..ab95be70d6c5 100644
--- a/js/xpconnect/tests/chrome/test_scripterror.html
+++ b/js/xpconnect/tests/chrome/test_scripterror.html
@@ -38,7 +38,7 @@ function hasExpectedProperties(message, exception) {
   is(message.sourceName, location.href, "has correct sourceName/filename");
   ok(message.lineNumber > 0, "has lineNumber");
 
-  is(message.innerWindowID, window.windowUtils.currentInnerWindowID,
+  is(message.innerWindowID, window.windowGlobalChild.innerWindowId,
      "correct innerWindowID");
 }
 
diff --git a/netwerk/protocol/http/HttpBaseChannel.cpp b/netwerk/protocol/http/HttpBaseChannel.cpp
index 14e0b9acfc5a..8bf140ca09a0 100644
--- a/netwerk/protocol/http/HttpBaseChannel.cpp
+++ b/netwerk/protocol/http/HttpBaseChannel.cpp
@@ -1439,12 +1439,11 @@ NS_IMETHODIMP HttpBaseChannel::GetTopLevelContentWindowId(uint64_t* aWindowId) {
     if (loadContext) {
       nsCOMPtr<mozIDOMWindowProxy> topWindow;
       loadContext->GetTopWindow(getter_AddRefs(topWindow));
-      nsCOMPtr<nsIDOMWindowUtils> windowUtils;
       if (topWindow) {
-        windowUtils = nsGlobalWindowOuter::Cast(topWindow)->WindowUtils();
-      }
-      if (windowUtils) {
-        windowUtils->GetCurrentInnerWindowID(&mContentWindowId);
+        if (nsPIDOMWindowInner* inner =
+                nsPIDOMWindowOuter::From(topWindow)->GetCurrentInnerWindow()) {
+          mContentWindowId = inner->WindowID();
+        }
       }
     }
   }
diff --git a/remote/domains/content/Page.jsm b/remote/domains/content/Page.jsm
index 7bcc49e86c54..8a3c85ce26f4 100644
--- a/remote/domains/content/Page.jsm
+++ b/remote/domains/content/Page.jsm
@@ -241,7 +241,7 @@ class Page extends ContentProcessDomain {
     const window = defaultContext.window;
 
     const executionContextId = Runtime._onContextCreated("context-created", {
-      windowId: window.windowUtils.currentInnerWindowID,
+      windowId: window.windowGlobalChild.innerWindowId,
       window,
       isDefault: false,
       contextName: worldName,
diff --git a/remote/domains/content/Runtime.jsm b/remote/domains/content/Runtime.jsm
index 6f4980e892d6..42a0aed73daa 100644
--- a/remote/domains/content/Runtime.jsm
+++ b/remote/domains/content/Runtime.jsm
@@ -89,7 +89,7 @@ class Runtime extends ContentProcessDomain {
       // after we replied to `enable` request.
       executeSoon(() => {
         this._onContextCreated("context-created", {
-          windowId: this.content.windowUtils.currentInnerWindowID,
+          windowId: this.content.windowGlobalChild.innerWindowId,
           window: this.content,
           isDefault: true,
         });
@@ -325,8 +325,7 @@ class Runtime extends ContentProcessDomain {
 
   _getDefaultContextForWindow(innerWindowId) {
     if (!innerWindowId) {
-      const { windowUtils } = this.content;
-      innerWindowId = windowUtils.currentInnerWindowID;
+      innerWindowId = this.content.windowGlobalChild.innerWindowId;
     }
     const curContexts = this.innerWindowIdToContexts.get(innerWindowId);
     if (curContexts) {
diff --git a/remote/domains/content/runtime/ExecutionContext.jsm b/remote/domains/content/runtime/ExecutionContext.jsm
index 44e62d4314a4..6d2f1b0d3ada 100644
--- a/remote/domains/content/runtime/ExecutionContext.jsm
+++ b/remote/domains/content/runtime/ExecutionContext.jsm
@@ -48,7 +48,7 @@ class ExecutionContext {
     // Here, we assume that debuggee is a window object and we will propably have
     // to adapt that once we cover workers or contexts that aren't a document.
     this.window = debuggee;
-    this.windowId = debuggee.windowUtils.currentInnerWindowID;
+    this.windowId = debuggee.windowGlobalChild.innerWindowId;
     this.id = id;
     this.frameId = debuggee.docShell.browsingContext.id.toString();
     this.isDefault = isDefault;
diff --git a/remote/observers/ContextObserver.jsm b/remote/observers/ContextObserver.jsm
index 9428b1ad55a1..e98f94ebbb61 100644
--- a/remote/observers/ContextObserver.jsm
+++ b/remote/observers/ContextObserver.jsm
@@ -74,8 +74,8 @@ class ContextObserver {
 
   handleEvent({ type, target, persisted }) {
     const window = target.defaultView;
-    const frameId = window.docShell.browsingContext.id;
-    const id = window.windowUtils.currentInnerWindowID;
+    const frameId = window.browsingContext.id;
+    const id = window.windowGlobalChild.innerWindowId;
 
     switch (type) {
       case "DOMWindowCreated":
diff --git a/testing/specialpowers/content/SpecialPowersChild.jsm b/testing/specialpowers/content/SpecialPowersChild.jsm
index 757c5aba47ca..ec7fbef4e608 100644
--- a/testing/specialpowers/content/SpecialPowersChild.jsm
+++ b/testing/specialpowers/content/SpecialPowersChild.jsm
@@ -231,7 +231,7 @@ class SpecialPowersChild extends JSWindowActorChild {
     let window = this.contentWindow;
     // We should not invoke the getter.
     if (!("SpecialPowers" in window.wrappedJSObject)) {
-      this._windowID = window.windowUtils.currentInnerWindowID;
+      this._windowID = window.windowGlobalChild.innerWindowId;
 
       defineSpecialPowers(this);
       if (this.IsInNestedFrame) {
diff --git a/testing/specialpowers/content/WrapPrivileged.jsm b/testing/specialpowers/content/WrapPrivileged.jsm
index 881d30383e41..5c6fd4df7d2a 100644
--- a/testing/specialpowers/content/WrapPrivileged.jsm
+++ b/testing/specialpowers/content/WrapPrivileged.jsm
@@ -132,7 +132,9 @@ function wrapPrivileged(obj, win) {
   let { windowID, proxies, handler } = perWindowInfo.get(win) || {};
   // |windowUtils| is undefined if |win| is a non-window object
   // such as a sandbox.
-  let currentID = win.windowUtils ? win.windowUtils.currentInnerWindowID : 0;
+  let currentID = win.windowGlobalChild
+    ? win.windowGlobalChild.innerWindowId
+    : 0;
   // Values are dead objects if the inner window is changed.
   if (windowID !== currentID) {
     windowID = currentID;
diff --git a/toolkit/components/extensions/ExtensionUtils.jsm b/toolkit/components/extensions/ExtensionUtils.jsm
index baa7362be400..370785fc42fd 100644
--- a/toolkit/components/extensions/ExtensionUtils.jsm
+++ b/toolkit/components/extensions/ExtensionUtils.jsm
@@ -109,7 +109,7 @@ class DefaultMap extends Map {
 }
 
 function getInnerWindowID(window) {
-  return window.windowUtils.currentInnerWindowID;
+  return window.windowGlobalChild?.innerWindowId;
 }
 
 /**
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_contentscript_devtools_metadata.html b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_devtools_metadata.html
index 6a135ef47ad2..f2a2de0e05c6 100644
--- a/toolkit/components/extensions/test/mochitest/test_ext_contentscript_devtools_metadata.html
+++ b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_devtools_metadata.html
@@ -48,7 +48,7 @@ add_task(async function test_contentscript_devtools_sandbox_metadata() {
 
   let win = window.open("file_sample.html");
 
-  let innerWindowID = SpecialPowers.getDOMWindowUtils(win).currentInnerWindowID;
+  let innerWindowID = SpecialPowers.wrap(win).windowGlobalChild.innerWindowId;
 
   await extension.awaitFinish("contentScript.executed");
 
diff --git a/toolkit/components/extensions/test/xpcshell/test_ext_contexts_gc.js b/toolkit/components/extensions/test/xpcshell/test_ext_contexts_gc.js
index 9dbafc664732..521b7db4e900 100644
--- a/toolkit/components/extensions/test/xpcshell/test_ext_contexts_gc.js
+++ b/toolkit/components/extensions/test/xpcshell/test_ext_contexts_gc.js
@@ -191,7 +191,8 @@ add_task(async function test_ExtensionPageContextChild_in_child_frame() {
     let frame = this.content.document.querySelector(
       "iframe[src*='iframe.html']"
     );
-    let innerWindowID = frame.contentWindow.windowUtils.currentInnerWindowID;
+    let innerWindowID =
+      frame.browsingContext.currentWindowContext.innerWindowId;
     let context = ExtensionPageChild.extensionContexts.get(innerWindowID);
 
     Assert.ok(context, "Got extension page context for child frame");
@@ -237,7 +238,7 @@ add_task(async function test_ExtensionPageContextChild_in_toplevel() {
       "resource://gre/modules/ExtensionPageChild.jsm"
     );
 
-    let innerWindowID = this.content.windowUtils.currentInnerWindowID;
+    let innerWindowID = this.content.windowGlobalChild.innerWindowId;
     let context = ExtensionPageChild.extensionContexts.get(innerWindowID);
 
     Assert.ok(context, "Got extension page context for top-level document");
diff --git a/toolkit/components/passwordmgr/InsecurePasswordUtils.jsm b/toolkit/components/passwordmgr/InsecurePasswordUtils.jsm
index 367afae959ac..66bea38ad8ab 100644
--- a/toolkit/components/passwordmgr/InsecurePasswordUtils.jsm
+++ b/toolkit/components/passwordmgr/InsecurePasswordUtils.jsm
@@ -51,7 +51,7 @@ this.InsecurePasswordUtils = {
    *         Inner ID for the given window.
    */
   _getInnerWindowId(window) {
-    return window.windowUtils.currentInnerWindowID;
+    return window.windowGlobalChild.innerWindowId;
   },
 
   _sendWebConsoleMessage(messageTag, domDoc) {
diff --git a/toolkit/components/reader/AboutReader.jsm b/toolkit/components/reader/AboutReader.jsm
index fb49b1de2f73..4d89b01fc2f3 100644
--- a/toolkit/components/reader/AboutReader.jsm
+++ b/toolkit/components/reader/AboutReader.jsm
@@ -69,7 +69,7 @@ var AboutReader = function(actor, articlePromise) {
 
   this._docRef = Cu.getWeakReference(doc);
   this._winRef = Cu.getWeakReference(win);
-  this._innerWindowId = win.windowUtils.currentInnerWindowID;
+  this._innerWindowId = win.windowGlobalChild.innerWindowId;
 
   this._article = null;
   this._languagePromise = new Promise(resolve => {
diff --git a/toolkit/mozapps/extensions/amInstallTrigger.jsm b/toolkit/mozapps/extensions/amInstallTrigger.jsm
index 9ed17c2a3bd8..8acfa65ab371 100644
--- a/toolkit/mozapps/extensions/amInstallTrigger.jsm
+++ b/toolkit/mozapps/extensions/amInstallTrigger.jsm
@@ -37,8 +37,7 @@ function CallbackObject(id, callback, mediator) {
 }
 
 function RemoteMediator(window) {
-  let utils = window.windowUtils;
-  this._windowID = utils.currentInnerWindowID;
+  this._windowID = window.windowGlobalChild.innerWindowId;
 
   this.mm = window.docShell.messageManager;
   this.mm.addWeakMessageListener(MSG_INSTALL_CALLBACK, this);