diff --git a/browser/base/content/test/static/browser_all_files_referenced.js b/browser/base/content/test/static/browser_all_files_referenced.js
index 2c0484771e4e..b2b760130744 100644
--- a/browser/base/content/test/static/browser_all_files_referenced.js
+++ b/browser/base/content/test/static/browser_all_files_referenced.js
@@ -363,7 +363,7 @@ if (!isDevtools) {
   // resource://devtools/shared/worker/loader.js,
   // resource://devtools/shared/loader/builtin-modules.js
   if (!AppConstants.ENABLE_WEBDRIVER) {
-    whitelist.add("resource://gre/modules/jsdebugger.jsm");
+    whitelist.add("resource://gre/modules/jsdebugger.sys.mjs");
   }
 }
 
diff --git a/devtools/client/memory/test/xpcshell/head.js b/devtools/client/memory/test/xpcshell/head.js
index 1c38531dee06..179ea544ff72 100644
--- a/devtools/client/memory/test/xpcshell/head.js
+++ b/devtools/client/memory/test/xpcshell/head.js
@@ -17,8 +17,8 @@ var { FileUtils } = ChromeUtils.import("resource://gre/modules/FileUtils.jsm");
 var { expectState } = require("resource://devtools/server/actors/common.js");
 var HeapSnapshotFileUtils = require("resource://devtools/shared/heapsnapshot/HeapSnapshotFileUtils.js");
 var HeapAnalysesClient = require("resource://devtools/shared/heapsnapshot/HeapAnalysesClient.js");
-var { addDebuggerToGlobal } = ChromeUtils.import(
-  "resource://gre/modules/jsdebugger.jsm"
+var { addDebuggerToGlobal } = ChromeUtils.importESModule(
+  "resource://gre/modules/jsdebugger.sys.mjs"
 );
 var Store = require("resource://devtools/client/memory/store.js");
 var { L10N } = require("resource://devtools/client/memory/utils.js");
diff --git a/devtools/docs/user/debugger-api/tutorial-allocation-log-tree/index.rst b/devtools/docs/user/debugger-api/tutorial-allocation-log-tree/index.rst
index 0285055ef7cb..711e6f245b0c 100644
--- a/devtools/docs/user/debugger-api/tutorial-allocation-log-tree/index.rst
+++ b/devtools/docs/user/debugger-api/tutorial-allocation-log-tree/index.rst
@@ -34,8 +34,8 @@ This page shows how to use the :doc:`Debugger API <../index>` to show how many o
 
     // This defines the 'Debugger' constructor in this
     // Scratchpad; it doesn't actually start debugging anything.
-    const { addDebuggerToGlobal } = ChromeUtils.import(
-      'resource://gre/modules/jsdebugger.jsm'
+    const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+      'resource://gre/modules/jsdebugger.sys.mjs'
     );
     addDebuggerToGlobal(window);
 
diff --git a/devtools/docs/user/debugger-api/tutorial-breakpoint/index.rst b/devtools/docs/user/debugger-api/tutorial-breakpoint/index.rst
index 3985794f9319..fb56b14a3f24 100644
--- a/devtools/docs/user/debugger-api/tutorial-breakpoint/index.rst
+++ b/devtools/docs/user/debugger-api/tutorial-breakpoint/index.rst
@@ -40,8 +40,8 @@ This tutorial was tested against Firefox 58 Beta and Nightly. It does not work i
 
   .. code-block:: javascript
 
-    const { addDebuggerToGlobal } = ChromeUtils.import(
-      "resource://gre/modules/jsdebugger.jsm"
+    const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+      "resource://gre/modules/jsdebugger.sys.mjs"
     );
     const { console } = ChromeUtils.import(
       "resource://gre/modules/Console.jsm"
diff --git a/devtools/platform/IJSDebugger.idl b/devtools/platform/IJSDebugger.idl
index 92d5e472c67f..ec309a315f92 100644
--- a/devtools/platform/IJSDebugger.idl
+++ b/devtools/platform/IJSDebugger.idl
@@ -6,8 +6,8 @@
 
 /**
  * Do not use this interface. Instead, write:
- *     const { addDebuggerToGlobal } = ChromeUtils.import(
- *       "resource://gre/modules/jsdebugger.jsm"
+ *     const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+ *       "resource://gre/modules/jsdebugger.sys.mjs"
  *     );
  *     addDebuggerToGlobal(global);
  */
diff --git a/devtools/platform/jsdebugger.jsm b/devtools/platform/jsdebugger.sys.mjs
similarity index 91%
rename from devtools/platform/jsdebugger.jsm
rename to devtools/platform/jsdebugger.sys.mjs
index 53be813286d4..a4af1fdbc3d4 100644
--- a/devtools/platform/jsdebugger.jsm
+++ b/devtools/platform/jsdebugger.sys.mjs
@@ -3,14 +3,10 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-"use strict";
-
-var EXPORTED_SYMBOLS = ["addDebuggerToGlobal", "addSandboxedDebuggerToGlobal"];
-
 /*
  * This is the js module for Debugger. Import it like so:
- *   const { addDebuggerToGlobal } = ChromeUtils.import(
- *     "resource://gre/modules/jsdebugger.jsm"
+ *   const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+ *     "resource://gre/modules/jsdebugger.sys.mjs"
  *   );
  *   addDebuggerToGlobal(globalThis);
  *
@@ -23,14 +19,15 @@ var EXPORTED_SYMBOLS = ["addDebuggerToGlobal", "addSandboxedDebuggerToGlobal"];
  */
 
 const init = Cc["@mozilla.org/jsdebugger;1"].createInstance(Ci.IJSDebugger);
-function addDebuggerToGlobal(global) {
+
+export function addDebuggerToGlobal(global) {
   init.addClass(global);
   initPromiseDebugging(global);
 }
 
 // Defines the Debugger in a sandbox global in a separate compartment. This
 // ensures the debugger and debuggee are in different compartments.
-function addSandboxedDebuggerToGlobal(global) {
+export function addSandboxedDebuggerToGlobal(global) {
   const sb = Cu.Sandbox(global, { freshCompartment: true });
   addDebuggerToGlobal(sb);
   global.Debugger = sb.Debugger;
diff --git a/devtools/platform/moz.build b/devtools/platform/moz.build
index 7e171a7d44a0..33be638e5b4b 100644
--- a/devtools/platform/moz.build
+++ b/devtools/platform/moz.build
@@ -23,7 +23,7 @@ XPCOM_MANIFESTS += [
 ]
 
 EXTRA_JS_MODULES += [
-    "jsdebugger.jsm",
+    "jsdebugger.sys.mjs",
 ]
 
 # The /devtools/moz.build opted in to treatment of devtools as a browser
diff --git a/devtools/platform/tests/xpcshell/test_nativewrappers.js b/devtools/platform/tests/xpcshell/test_nativewrappers.js
index 69af71822b80..973f33a46129 100644
--- a/devtools/platform/tests/xpcshell/test_nativewrappers.js
+++ b/devtools/platform/tests/xpcshell/test_nativewrappers.js
@@ -1,8 +1,8 @@
 "use strict";
 
 function run_test() {
-  const { addDebuggerToGlobal } = ChromeUtils.import(
-    "resource://gre/modules/jsdebugger.jsm"
+  const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+    "resource://gre/modules/jsdebugger.sys.mjs"
   );
 
   Services.prefs.setBoolPref("security.allow_eval_with_system_principal", true);
diff --git a/devtools/server/actors/webconsole.js b/devtools/server/actors/webconsole.js
index 0c7406111af2..8aaaf5beb98e 100644
--- a/devtools/server/actors/webconsole.js
+++ b/devtools/server/actors/webconsole.js
@@ -215,7 +215,7 @@ const WebConsoleActor = ActorClassWithSpec(webconsoleSpec, {
   /**
    * Debugger instance.
    *
-   * @see jsdebugger.jsm
+   * @see jsdebugger.sys.mjs
    */
   dbg: null,
 
diff --git a/devtools/server/tests/chrome/test_Debugger.Script.prototype.global.html b/devtools/server/tests/chrome/test_Debugger.Script.prototype.global.html
index dda20a12ec4f..d403d6b4a3ba 100644
--- a/devtools/server/tests/chrome/test_Debugger.Script.prototype.global.html
+++ b/devtools/server/tests/chrome/test_Debugger.Script.prototype.global.html
@@ -16,7 +16,7 @@ Debugger.Script.prototype.global should return innerize globals, not WindowProxi
 <script>
 "use strict";
 
-const {addDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+const {addDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
 addDebuggerToGlobal(globalThis);
 
 window.onload = function() {
diff --git a/devtools/server/tests/chrome/test_Debugger.Source.prototype.elementAttribute.html b/devtools/server/tests/chrome/test_Debugger.Source.prototype.elementAttribute.html
index 7704764a6ab0..cb9c2bbcdcd9 100644
--- a/devtools/server/tests/chrome/test_Debugger.Source.prototype.elementAttribute.html
+++ b/devtools/server/tests/chrome/test_Debugger.Source.prototype.elementAttribute.html
@@ -17,7 +17,7 @@ element to which code is attached (if any), and how.
 <script>
 "use strict";
 
-const {addSandboxedDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+const {addSandboxedDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
 addSandboxedDebuggerToGlobal(globalThis);
 
 window.onload = function() {
diff --git a/devtools/server/tests/chrome/test_Debugger.Source.prototype.introductionScript.html b/devtools/server/tests/chrome/test_Debugger.Source.prototype.introductionScript.html
index fde093fc60f7..09c23b52535d 100644
--- a/devtools/server/tests/chrome/test_Debugger.Source.prototype.introductionScript.html
+++ b/devtools/server/tests/chrome/test_Debugger.Source.prototype.introductionScript.html
@@ -17,7 +17,7 @@ behave when 'eval' is called with no scripted frames active at all.
 <script>
 "use strict";
 
-const {addDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+const {addDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
 addDebuggerToGlobal(globalThis);
 
 window.onload = function() {
diff --git a/devtools/server/tests/chrome/test_Debugger.Source.prototype.introductionType.html b/devtools/server/tests/chrome/test_Debugger.Source.prototype.introductionType.html
index d2df439651fb..1057d4b94f8d 100644
--- a/devtools/server/tests/chrome/test_Debugger.Source.prototype.introductionType.html
+++ b/devtools/server/tests/chrome/test_Debugger.Source.prototype.introductionType.html
@@ -18,7 +18,7 @@ JavaScrip appearing in an inline event handler attribute.
 <script>
 "use strict";
 
-const {addSandboxedDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+const {addSandboxedDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
 addSandboxedDebuggerToGlobal(globalThis);
 
 let dbg;
diff --git a/devtools/server/tests/chrome/test_executeInGlobal-outerized_this.html b/devtools/server/tests/chrome/test_executeInGlobal-outerized_this.html
index 9b3312e2601f..6a846596b20b 100644
--- a/devtools/server/tests/chrome/test_executeInGlobal-outerized_this.html
+++ b/devtools/server/tests/chrome/test_executeInGlobal-outerized_this.html
@@ -18,7 +18,7 @@ object.
 <script>
 "use strict";
 
-const {addDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+const {addDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
 addDebuggerToGlobal(globalThis);
 
 window.onload = function() {
diff --git a/devtools/server/tests/chrome/test_makeGlobalObjectReference.html b/devtools/server/tests/chrome/test_makeGlobalObjectReference.html
index a59f52c818a1..d8007984272a 100644
--- a/devtools/server/tests/chrome/test_makeGlobalObjectReference.html
+++ b/devtools/server/tests/chrome/test_makeGlobalObjectReference.html
@@ -17,7 +17,7 @@ Debugger.prototype.makeGlobalObjectReference should dereference WindowProxy
 <script>
 "use strict";
 
-const {addSandboxedDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+const {addSandboxedDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
 addSandboxedDebuggerToGlobal(globalThis);
 
 window.onload = function() {
diff --git a/devtools/server/tests/chrome/test_unsafeDereference.html b/devtools/server/tests/chrome/test_unsafeDereference.html
index e41668fb315b..eca1e7d43e54 100644
--- a/devtools/server/tests/chrome/test_unsafeDereference.html
+++ b/devtools/server/tests/chrome/test_unsafeDereference.html
@@ -18,7 +18,7 @@ xray wrapper.
 <script>
 "use strict";
 
-const {addDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+const {addDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
 addDebuggerToGlobal(globalThis);
 
 window.onload = function() {
diff --git a/devtools/server/tests/xpcshell/head_dbg.js b/devtools/server/tests/xpcshell/head_dbg.js
index fb66557563d9..47321c2a16d7 100644
--- a/devtools/server/tests/xpcshell/head_dbg.js
+++ b/devtools/server/tests/xpcshell/head_dbg.js
@@ -57,8 +57,8 @@ const {
   CommandsFactory,
 } = require("resource://devtools/shared/commands/commands-factory.js");
 
-const { addDebuggerToGlobal } = ChromeUtils.import(
-  "resource://gre/modules/jsdebugger.jsm"
+const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+  "resource://gre/modules/jsdebugger.sys.mjs"
 );
 
 const { AddonTestUtils } = ChromeUtils.import(
diff --git a/devtools/server/tests/xpcshell/test_getyoungestframe.js b/devtools/server/tests/xpcshell/test_getyoungestframe.js
index 9dcb27784a41..8af9981e22cf 100644
--- a/devtools/server/tests/xpcshell/test_getyoungestframe.js
+++ b/devtools/server/tests/xpcshell/test_getyoungestframe.js
@@ -4,8 +4,8 @@ function run_test() {
   registerCleanupFunction(() => {
     Services.prefs.clearUserPref("security.allow_eval_with_system_principal");
   });
-  const { addDebuggerToGlobal } = ChromeUtils.import(
-    "resource://gre/modules/jsdebugger.jsm"
+  const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+    "resource://gre/modules/jsdebugger.sys.mjs"
   );
   addDebuggerToGlobal(globalThis);
   const xpcInspector = Cc["@mozilla.org/jsinspector;1"].getService(
diff --git a/devtools/server/tests/xpcshell/test_nativewrappers.js b/devtools/server/tests/xpcshell/test_nativewrappers.js
index da35b2f281de..ae247fb1543e 100644
--- a/devtools/server/tests/xpcshell/test_nativewrappers.js
+++ b/devtools/server/tests/xpcshell/test_nativewrappers.js
@@ -4,8 +4,8 @@ function run_test() {
   registerCleanupFunction(() => {
     Services.prefs.clearUserPref("security.allow_eval_with_system_principal");
   });
-  const { addDebuggerToGlobal } = ChromeUtils.import(
-    "resource://gre/modules/jsdebugger.jsm"
+  const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+    "resource://gre/modules/jsdebugger.sys.mjs"
   );
   addDebuggerToGlobal(globalThis);
   const g = createTestGlobal("test1");
diff --git a/devtools/server/tests/xpcshell/test_safe-getter.js b/devtools/server/tests/xpcshell/test_safe-getter.js
index 18571a3eb3da..7e0c0233678a 100644
--- a/devtools/server/tests/xpcshell/test_safe-getter.js
+++ b/devtools/server/tests/xpcshell/test_safe-getter.js
@@ -4,8 +4,8 @@ function run_test() {
   registerCleanupFunction(() => {
     Services.prefs.clearUserPref("security.allow_eval_with_system_principal");
   });
-  const { addDebuggerToGlobal } = ChromeUtils.import(
-    "resource://gre/modules/jsdebugger.jsm"
+  const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+    "resource://gre/modules/jsdebugger.sys.mjs"
   );
   addDebuggerToGlobal(globalThis);
   const g = createTestGlobal("test", {
diff --git a/devtools/shared/heapsnapshot/tests/xpcshell/head_heapsnapshot.js b/devtools/shared/heapsnapshot/tests/xpcshell/head_heapsnapshot.js
index 10d9915402b4..1dab9d406096 100644
--- a/devtools/shared/heapsnapshot/tests/xpcshell/head_heapsnapshot.js
+++ b/devtools/shared/heapsnapshot/tests/xpcshell/head_heapsnapshot.js
@@ -16,8 +16,8 @@ const { require } = ChromeUtils.import(
 );
 const { Match } = ChromeUtils.importESModule("resource://test/Match.sys.mjs");
 const { Census } = ChromeUtils.importESModule("resource://test/Census.sys.mjs");
-const { addDebuggerToGlobal } = ChromeUtils.import(
-  "resource://gre/modules/jsdebugger.jsm"
+const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+  "resource://gre/modules/jsdebugger.sys.mjs"
 );
 
 const DevToolsUtils = require("devtools/shared/DevToolsUtils");
diff --git a/devtools/shared/heapsnapshot/tests/xpcshell/test_ReadHeapSnapshot.js b/devtools/shared/heapsnapshot/tests/xpcshell/test_ReadHeapSnapshot.js
index 0371fe8a315f..b7a3c9c2f8fd 100644
--- a/devtools/shared/heapsnapshot/tests/xpcshell/test_ReadHeapSnapshot.js
+++ b/devtools/shared/heapsnapshot/tests/xpcshell/test_ReadHeapSnapshot.js
@@ -4,8 +4,8 @@
 // Test that we can read core dumps into HeapSnapshot instances.
 /* eslint-disable strict */
 if (typeof Debugger != "function") {
-  const { addDebuggerToGlobal } = ChromeUtils.import(
-    "resource://gre/modules/jsdebugger.jsm"
+  const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+    "resource://gre/modules/jsdebugger.sys.mjs"
   );
   addDebuggerToGlobal(globalThis);
 }
diff --git a/devtools/shared/heapsnapshot/tests/xpcshell/test_ReadHeapSnapshot_with_allocations.js b/devtools/shared/heapsnapshot/tests/xpcshell/test_ReadHeapSnapshot_with_allocations.js
index 4b5a36d577cb..273736abcd6e 100644
--- a/devtools/shared/heapsnapshot/tests/xpcshell/test_ReadHeapSnapshot_with_allocations.js
+++ b/devtools/shared/heapsnapshot/tests/xpcshell/test_ReadHeapSnapshot_with_allocations.js
@@ -6,8 +6,8 @@
 // into a HeapSnapshot.
 
 if (typeof Debugger != "function") {
-  const { addDebuggerToGlobal } = ChromeUtils.import(
-    "resource://gre/modules/jsdebugger.jsm"
+  const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+    "resource://gre/modules/jsdebugger.sys.mjs"
   );
   addDebuggerToGlobal(globalThis);
 }
diff --git a/devtools/shared/heapsnapshot/tests/xpcshell/test_SaveHeapSnapshot.js b/devtools/shared/heapsnapshot/tests/xpcshell/test_SaveHeapSnapshot.js
index dce842a3c8cd..641b019a8e6f 100644
--- a/devtools/shared/heapsnapshot/tests/xpcshell/test_SaveHeapSnapshot.js
+++ b/devtools/shared/heapsnapshot/tests/xpcshell/test_SaveHeapSnapshot.js
@@ -4,8 +4,8 @@
 // Test the ChromeUtils interface.
 // eslint-disable-next-line
 if (typeof Debugger != "function") {
-  const { addDebuggerToGlobal } = ChromeUtils.import(
-    "resource://gre/modules/jsdebugger.jsm"
+  const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+    "resource://gre/modules/jsdebugger.sys.mjs"
   );
   addDebuggerToGlobal(globalThis);
 }
diff --git a/devtools/shared/loader/builtin-modules.js b/devtools/shared/loader/builtin-modules.js
index d67188f44ccf..257209fea75b 100644
--- a/devtools/shared/loader/builtin-modules.js
+++ b/devtools/shared/loader/builtin-modules.js
@@ -154,8 +154,8 @@ defineLazyGetter(exports.modules, "Debugger", () => {
   if (global.Debugger) {
     return global.Debugger;
   }
-  const { addDebuggerToGlobal } = ChromeUtils.import(
-    "resource://gre/modules/jsdebugger.jsm"
+  const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+    "resource://gre/modules/jsdebugger.sys.mjs"
   );
   addDebuggerToGlobal(global);
   return global.Debugger;
@@ -170,8 +170,8 @@ defineLazyGetter(exports.modules, "ChromeDebugger", () => {
     freshCompartment: true,
   });
 
-  const { addDebuggerToGlobal } = ChromeUtils.import(
-    "resource://gre/modules/jsdebugger.jsm"
+  const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+    "resource://gre/modules/jsdebugger.sys.mjs"
   );
   addDebuggerToGlobal(debuggerSandbox);
   return debuggerSandbox.Debugger;
diff --git a/devtools/shared/loader/worker-loader.js b/devtools/shared/loader/worker-loader.js
index 95ec3d488f17..014a58f792d6 100644
--- a/devtools/shared/loader/worker-loader.js
+++ b/devtools/shared/loader/worker-loader.js
@@ -390,8 +390,8 @@ var {
     });
     Cu.evalInSandbox(
       `
-const { addDebuggerToGlobal } = ChromeUtils.import(
-  'resource://gre/modules/jsdebugger.jsm'
+const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+  'resource://gre/modules/jsdebugger.sys.mjs'
 );
 addDebuggerToGlobal(globalThis);
 `,
diff --git a/devtools/shared/test-helpers/allocation-tracker.js b/devtools/shared/test-helpers/allocation-tracker.js
index 1a8b3af16e93..7d603a0c3575 100644
--- a/devtools/shared/test-helpers/allocation-tracker.js
+++ b/devtools/shared/test-helpers/allocation-tracker.js
@@ -40,8 +40,8 @@ const MemoryReporter = Cc["@mozilla.org/memory-reporter-manager;1"].getService(
 );
 
 const global = Cu.getGlobalForObject(this);
-const { addDebuggerToGlobal } = ChromeUtils.import(
-  "resource://gre/modules/jsdebugger.jsm"
+const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+  "resource://gre/modules/jsdebugger.sys.mjs"
 );
 addDebuggerToGlobal(global);
 
diff --git a/devtools/shared/tests/xpcshell/test_invisible_loader.js b/devtools/shared/tests/xpcshell/test_invisible_loader.js
index 0ba41a6b6e43..5e290d7d428d 100644
--- a/devtools/shared/tests/xpcshell/test_invisible_loader.js
+++ b/devtools/shared/tests/xpcshell/test_invisible_loader.js
@@ -3,8 +3,8 @@
 
 "use strict";
 
-const { addDebuggerToGlobal } = ChromeUtils.import(
-  "resource://gre/modules/jsdebugger.jsm"
+const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+  "resource://gre/modules/jsdebugger.sys.mjs"
 );
 addDebuggerToGlobal(globalThis);
 
diff --git a/devtools/shared/webconsole/test/xpcshell/test_js_property_provider.js b/devtools/shared/webconsole/test/xpcshell/test_js_property_provider.js
index 3cc51e762a75..ccc9b0c270e4 100644
--- a/devtools/shared/webconsole/test/xpcshell/test_js_property_provider.js
+++ b/devtools/shared/webconsole/test/xpcshell/test_js_property_provider.js
@@ -6,8 +6,8 @@ const {
   FallibleJSPropertyProvider: JSPropertyProvider,
 } = require("devtools/shared/webconsole/js-property-provider");
 
-const { addDebuggerToGlobal } = ChromeUtils.import(
-  "resource://gre/modules/jsdebugger.jsm"
+const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+  "resource://gre/modules/jsdebugger.sys.mjs"
 );
 addDebuggerToGlobal(globalThis);
 
diff --git a/dom/base/test/chrome/test_bug1346936.html b/dom/base/test/chrome/test_bug1346936.html
index c0f6e012928a..2c61c65237a2 100644
--- a/dom/base/test/chrome/test_bug1346936.html
+++ b/dom/base/test/chrome/test_bug1346936.html
@@ -25,7 +25,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=1346936
 
 /** Test for Bug 1346936 **/
 
-const {addDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+const {addDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
 addDebuggerToGlobal(globalThis);
 
 window.onload = function() {
diff --git a/dom/base/test/chrome/test_bug765993.html b/dom/base/test/chrome/test_bug765993.html
index 5a7ac4d13082..3325c3713d4d 100644
--- a/dom/base/test/chrome/test_bug765993.html
+++ b/dom/base/test/chrome/test_bug765993.html
@@ -25,7 +25,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=765993
 
 /** Test for Bug 765993 **/
 
-const {addDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+const {addDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
 addDebuggerToGlobal(globalThis);
 
 window.onload = function() {
diff --git a/dom/base/test/jsmodules/iframe_extractIntroType.html b/dom/base/test/jsmodules/iframe_extractIntroType.html
index e0182338777a..26c58aea6d4f 100644
--- a/dom/base/test/jsmodules/iframe_extractIntroType.html
+++ b/dom/base/test/jsmodules/iframe_extractIntroType.html
@@ -4,7 +4,7 @@
 <script>
   // Hook up the debugger statement to extract the calling script's
   // introductionType and set it in a property on the parent global.
-  const {addSandboxedDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+  const {addSandboxedDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
   addSandboxedDebuggerToGlobal(globalThis);
   var dbg = new Debugger;
   dbg.addDebuggee(parent);
diff --git a/dom/promise/tests/test_on_new_promise.html b/dom/promise/tests/test_on_new_promise.html
index d9c01c8f672e..195707f1d7f5 100644
--- a/dom/promise/tests/test_on_new_promise.html
+++ b/dom/promise/tests/test_on_new_promise.html
@@ -25,7 +25,7 @@ Debugger.prototype.onNewPromise.
      "[object Promise]",
      "We should have the native DOM promise implementation.");
 
-  const {addDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+  const {addDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
   var dbgGlobal = new Cu.Sandbox(document.nodePrincipal,
                                  {freshCompartment: true});
   addDebuggerToGlobal(dbgGlobal);
diff --git a/dom/promise/tests/test_on_promise_settled.html b/dom/promise/tests/test_on_promise_settled.html
index 11ddfc68b701..b40475206b04 100644
--- a/dom/promise/tests/test_on_promise_settled.html
+++ b/dom/promise/tests/test_on_promise_settled.html
@@ -27,7 +27,7 @@ Debugger.prototype.onPromiseResolved.
      "[object Promise]",
      "We should have the native DOM promise implementation.");
 
-  const {addDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+  const {addDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
   var dbgGlobal = new Cu.Sandbox(document.nodePrincipal,
                                  {freshCompartment: true});
   addDebuggerToGlobal(dbgGlobal);
diff --git a/dom/promise/tests/test_on_promise_settled_duplicates.html b/dom/promise/tests/test_on_promise_settled_duplicates.html
index be83d49a96e4..e11f4eaa6016 100644
--- a/dom/promise/tests/test_on_promise_settled_duplicates.html
+++ b/dom/promise/tests/test_on_promise_settled_duplicates.html
@@ -26,7 +26,7 @@ Bug 1084065 - Test that Debugger.prototype.onPromiseResolved doesn't get dupes.
      "[object Promise]",
      "We should have the native DOM promise implementation.");
 
-  const {addDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+  const {addDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
   var dbgGlobal = new Cu.Sandbox(document.nodePrincipal,
                                  {freshCompartment: true});
   addDebuggerToGlobal(dbgGlobal);
diff --git a/dom/streams/test/xpcshell/head.js b/dom/streams/test/xpcshell/head.js
index 5365df6558f4..510cabe757ee 100644
--- a/dom/streams/test/xpcshell/head.js
+++ b/dom/streams/test/xpcshell/head.js
@@ -1,7 +1,7 @@
 "use strict";
 
-const { addDebuggerToGlobal } = ChromeUtils.import(
-  "resource://gre/modules/jsdebugger.jsm"
+const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+  "resource://gre/modules/jsdebugger.sys.mjs"
 );
 
 const SYSTEM_PRINCIPAL = Cc["@mozilla.org/systemprincipal;1"].createInstance(
diff --git a/js/src/doc/Debugger/Tutorial-Alloc-Log-Tree.md b/js/src/doc/Debugger/Tutorial-Alloc-Log-Tree.md
index f97f7f9603e8..635b8eca1b95 100644
--- a/js/src/doc/Debugger/Tutorial-Alloc-Log-Tree.md
+++ b/js/src/doc/Debugger/Tutorial-Alloc-Log-Tree.md
@@ -20,8 +20,8 @@ them.
     ```js
     // This simply defines the 'Debugger' constructor in this
     // Scratchpad; it doesn't actually start debugging anything.
-    const { addDebuggerToGlobal } = ChromeUtils.import(
-      'resource://gre/modules/jsdebugger.jsm'
+    const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+      'resource://gre/modules/jsdebugger.sys.mjs'
     );
     addDebuggerToGlobal(window);
 
diff --git a/js/src/doc/Debugger/Tutorial-Breakpoint.md b/js/src/doc/Debugger/Tutorial-Breakpoint.md
index 4a607cf68c55..b37c7fb51ac2 100644
--- a/js/src/doc/Debugger/Tutorial-Breakpoint.md
+++ b/js/src/doc/Debugger/Tutorial-Breakpoint.md
@@ -44,8 +44,8 @@ This tutorial was tested against Firefox 58 Beta and Nightly. It does not work i
 5.  Click on the Scratchpad panel and enter the following code:
 
     ```js
-    const { addDebuggerToGlobal } = ChromeUtils.import(
-      "resource://gre/modules/jsdebugger.jsm"
+    const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+      "resource://gre/modules/jsdebugger.sys.mjs"
     );
     const { console } = ChromeUtils.import(
       "resource://gre/modules/Console.jsm"
diff --git a/js/src/doc/Debugger/Tutorial-Debugger-Statement.md b/js/src/doc/Debugger/Tutorial-Debugger-Statement.md
index 4d0a70f7ee07..524ca6d99ca3 100644
--- a/js/src/doc/Debugger/Tutorial-Debugger-Statement.md
+++ b/js/src/doc/Debugger/Tutorial-Debugger-Statement.md
@@ -31,8 +31,8 @@ page whenever it executes a JavaScript `debugger;` statement.
     ```js
     // This simply defines 'Debugger' in this Scratchpad;
     // it doesn't actually start debugging anything.
-    const { addDebuggerToGlobal } = ChromeUtils.import(
-      "resource://gre/modules/jsdebugger.jsm"
+    const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+      "resource://gre/modules/jsdebugger.sys.mjs"
     );
     addDebuggerToGlobal(window);
 
diff --git a/js/xpconnect/tests/chrome/test_evalInSandbox.xhtml b/js/xpconnect/tests/chrome/test_evalInSandbox.xhtml
index d622feccf48b..67676ae7816c 100644
--- a/js/xpconnect/tests/chrome/test_evalInSandbox.xhtml
+++ b/js/xpconnect/tests/chrome/test_evalInSandbox.xhtml
@@ -177,7 +177,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=533596
       outerSB.sop = this;
       Cu.evalInSandbox('checkExplicitVersions();', outerSB);
 
-      const {addDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+      const {addDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
       addDebuggerToGlobal(globalThis);
 
       try {
diff --git a/js/xpconnect/tests/chrome/test_onGarbageCollection.html b/js/xpconnect/tests/chrome/test_onGarbageCollection.html
index 42d2ea851fb4..ce056ed354de 100644
--- a/js/xpconnect/tests/chrome/test_onGarbageCollection.html
+++ b/js/xpconnect/tests/chrome/test_onGarbageCollection.html
@@ -24,8 +24,8 @@
       }
     );
     Cu.evalInSandbox(`
-const { addDebuggerToGlobal } = ChromeUtils.import(
-  'resource://gre/modules/jsdebugger.jsm'
+const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+  'resource://gre/modules/jsdebugger.sys.mjs'
 );
 addDebuggerToGlobal(globalThis);
 `, sandbox
diff --git a/js/xpconnect/tests/unit/head_ongc.js b/js/xpconnect/tests/unit/head_ongc.js
index 61b5fd5efc3e..146a15eb4fad 100644
--- a/js/xpconnect/tests/unit/head_ongc.js
+++ b/js/xpconnect/tests/unit/head_ongc.js
@@ -1,4 +1,4 @@
-var {addDebuggerToGlobal, addSandboxedDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+var {addDebuggerToGlobal, addSandboxedDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
 
 const testingFunctions = Cu.getJSTestingFunctions();
 const systemPrincipal = Cc["@mozilla.org/systemprincipal;1"].createInstance(Ci.nsIPrincipal);
diff --git a/js/xpconnect/tests/unit/test_import_devtools_loader.js b/js/xpconnect/tests/unit/test_import_devtools_loader.js
index 29facfc1e2d4..7c0b39e05bab 100644
--- a/js/xpconnect/tests/unit/test_import_devtools_loader.js
+++ b/js/xpconnect/tests/unit/test_import_devtools_loader.js
@@ -2,8 +2,8 @@
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
 
-const { addDebuggerToGlobal } = ChromeUtils.import(
-  "resource://gre/modules/jsdebugger.jsm"
+const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+  "resource://gre/modules/jsdebugger.sys.mjs"
 );
 addDebuggerToGlobal(this);
 
diff --git a/js/xpconnect/tests/unit/test_xray_SavedFrame-02.js b/js/xpconnect/tests/unit/test_xray_SavedFrame-02.js
index 8c62733bbe67..e9b575204428 100644
--- a/js/xpconnect/tests/unit/test_xray_SavedFrame-02.js
+++ b/js/xpconnect/tests/unit/test_xray_SavedFrame-02.js
@@ -1,7 +1,7 @@
 // Test calling SavedFrame getters across wrappers from privileged and
 // un-privileged globals.
 
-const {addDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+const {addDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
 addDebuggerToGlobal(globalThis);
 
 const lowP = Services.scriptSecurityManager.createNullPrincipal({});
diff --git a/js/xpconnect/tests/unit/test_xray_SavedFrame.js b/js/xpconnect/tests/unit/test_xray_SavedFrame.js
index b1d22f71a153..85c91a2aa1ea 100644
--- a/js/xpconnect/tests/unit/test_xray_SavedFrame.js
+++ b/js/xpconnect/tests/unit/test_xray_SavedFrame.js
@@ -1,7 +1,7 @@
 // Bug 1117242: Test calling SavedFrame getters from globals that don't subsume
 // that frame's principals.
 
-const {addDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+const {addDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
 addDebuggerToGlobal(globalThis);
 
 const lowP = Services.scriptSecurityManager.createNullPrincipal({});
diff --git a/remote/cdp/domains/content/Runtime.sys.mjs b/remote/cdp/domains/content/Runtime.sys.mjs
index b8790f5a95d5..f18491e751f9 100644
--- a/remote/cdp/domains/content/Runtime.sys.mjs
+++ b/remote/cdp/domains/content/Runtime.sys.mjs
@@ -4,9 +4,7 @@
 
 import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
 
-const { addDebuggerToGlobal } = ChromeUtils.import(
-  "resource://gre/modules/jsdebugger.jsm"
-);
+import { addDebuggerToGlobal } from "resource://gre/modules/jsdebugger.sys.mjs";
 
 import { ContentProcessDomain } from "chrome://remote/content/cdp/domains/ContentProcessDomain.sys.mjs";
 
diff --git a/remote/webdriver-bidi/Realm.sys.mjs b/remote/webdriver-bidi/Realm.sys.mjs
index 3bcf5e88e3f2..e4924cecdd44 100644
--- a/remote/webdriver-bidi/Realm.sys.mjs
+++ b/remote/webdriver-bidi/Realm.sys.mjs
@@ -5,8 +5,8 @@
 import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
 
 const lazy = {};
-XPCOMUtils.defineLazyModuleGetters(lazy, {
-  addDebuggerToGlobal: "resource://gre/modules/jsdebugger.jsm",
+ChromeUtils.defineESModuleGetters(lazy, {
+  addDebuggerToGlobal: "resource://gre/modules/jsdebugger.sys.mjs",
 });
 
 XPCOMUtils.defineLazyGetter(lazy, "dbg", () => {
diff --git a/testing/modules/CoverageUtils.jsm b/testing/modules/CoverageUtils.jsm
index a9bc68c3090d..aeaeb5064130 100644
--- a/testing/modules/CoverageUtils.jsm
+++ b/testing/modules/CoverageUtils.jsm
@@ -7,8 +7,8 @@
 var EXPORTED_SYMBOLS = ["CoverageCollector"];
 
 /* globals Debugger */
-const { addDebuggerToGlobal } = ChromeUtils.import(
-  "resource://gre/modules/jsdebugger.jsm"
+const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+  "resource://gre/modules/jsdebugger.sys.mjs"
 );
 // eslint-disable-next-line mozilla/reject-globalThis-modification
 addDebuggerToGlobal(globalThis);