--- a/testing/marionette/accessibility.js
+++ b/testing/marionette/accessibility.js
@@ -1,22 +1,21 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * 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";
 
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
-ChromeUtils.import("resource://gre/modules/Log.jsm");
 
-const logger = Log.repository.getLogger("Marionette");
+const {ElementNotAccessibleError} = ChromeUtils.import("chrome://marionette/content/error.js", {});
+const {Log} = ChromeUtils.import("chrome://marionette/content/log.js", {});
 
-const {ElementNotAccessibleError} =
-    ChromeUtils.import("chrome://marionette/content/error.js", {});
+XPCOMUtils.defineLazyGetter(this, "logger", Log.get);
 
 XPCOMUtils.defineLazyGetter(this, "service", () => {
   try {
     return Cc["@mozilla.org/accessibilityService;1"]
         .getService(Ci.nsIAccessibilityService);
   } catch (e) {
     logger.warn("Accessibility module is not present");
     return undefined;

--- a/testing/marionette/driver.js
+++ b/testing/marionette/driver.js
@@ -1,16 +1,15 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * 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";
 /* global XPCNativeWrapper */
 
-ChromeUtils.import("resource://gre/modules/Log.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 
 ChromeUtils.import("chrome://marionette/content/accessibility.js");
 const {Addon} = ChromeUtils.import("chrome://marionette/content/addon.js", {});
 ChromeUtils.import("chrome://marionette/content/assert.js");
 ChromeUtils.import("chrome://marionette/content/atom.js");
 const {
@@ -42,26 +41,28 @@ const {
   UnsupportedOperationError,
   WebDriverError,
 } = ChromeUtils.import("chrome://marionette/content/error.js", {});
 ChromeUtils.import("chrome://marionette/content/evaluate.js");
 const {pprint} = ChromeUtils.import("chrome://marionette/content/format.js", {});
 ChromeUtils.import("chrome://marionette/content/interaction.js");
 ChromeUtils.import("chrome://marionette/content/l10n.js");
 ChromeUtils.import("chrome://marionette/content/legacyaction.js");
+const {Log} = ChromeUtils.import("chrome://marionette/content/log.js", {});
 ChromeUtils.import("chrome://marionette/content/modal.js");
 const {MarionettePrefs} = ChromeUtils.import("chrome://marionette/content/prefs.js", {});
 ChromeUtils.import("chrome://marionette/content/proxy.js");
 ChromeUtils.import("chrome://marionette/content/reftest.js");
 ChromeUtils.import("chrome://marionette/content/session.js");
 const {
   PollPromise,
   TimedPromise,
 } = ChromeUtils.import("chrome://marionette/content/sync.js", {});
 
+XPCOMUtils.defineLazyGetter(this, "logger", Log.get);
 XPCOMUtils.defineLazyGlobalGetters(this, ["URL"]);
 
 this.EXPORTED_SYMBOLS = ["GeckoDriver"];
 
 const APP_ID_FIREFOX = "{ec8030f7-c20a-464f-9b0e-13a3a9e97384}";
 
 const FRAME_SCRIPT = "chrome://marionette/content/listener.js";
 const XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
@@ -71,17 +72,16 @@ const SUPPORTED_STRATEGIES = new Set([
   element.Strategy.Selector,
   element.Strategy.ID,
   element.Strategy.TagName,
   element.Strategy.XPath,
   element.Strategy.Anon,
   element.Strategy.AnonAttribute,
 ]);
 
-const logger = Log.repository.getLogger("Marionette");
 const globalMessageManager = Services.mm;
 
 /**
  * The Marionette WebDriver services provides a standard conforming
  * implementation of the W3C WebDriver specification.
  *
  * @see {@link https://w3c.github.io/webdriver/webdriver-spec.html}
  * @namespace driver

--- a/testing/marionette/evaluate.js
+++ b/testing/marionette/evaluate.js
@@ -1,30 +1,30 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * 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";
 
-ChromeUtils.import("resource://gre/modules/Log.jsm");
 ChromeUtils.import("resource://gre/modules/NetUtil.jsm");
 ChromeUtils.import("resource://gre/modules/Timer.jsm");
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 
 ChromeUtils.import("chrome://marionette/content/assert.js");
 const {
   element,
   WebElement,
 } = ChromeUtils.import("chrome://marionette/content/element.js", {});
 const {
   JavaScriptError,
   ScriptTimeoutError,
 } = ChromeUtils.import("chrome://marionette/content/error.js", {});
+const {Log} = ChromeUtils.import("chrome://marionette/content/log.js", {});
 
-const log = Log.repository.getLogger("Marionette");
+XPCOMUtils.defineLazyGetter(this, "log", Log.get);
 
 this.EXPORTED_SYMBOLS = ["evaluate", "sandbox", "Sandboxes"];
 
 const ARGUMENTS = "__webDriverArguments";
 const CALLBACK = "__webDriverCallback";
 const COMPLETE = "__webDriverComplete";
 const DEFAULT_TIMEOUT = 10000; // ms
 const FINISH = "finish";

--- a/testing/marionette/format.js
+++ b/testing/marionette/format.js
@@ -1,20 +1,22 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * 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";
 
-ChromeUtils.import("resource://gre/modules/Log.jsm");
+ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
+
+const {Log} = ChromeUtils.import("chrome://marionette/content/log.js", {});
+
+XPCOMUtils.defineLazyGetter(this, "log", Log.get);
 
 this.EXPORTED_SYMBOLS = ["pprint", "truncate"];
 
-const log = Log.repository.getLogger("Marionette");
-
 const MAX_STRING_LENGTH = 250;
 
 /**
  * Pretty-print values passed to template strings.
  *
  * Usage:
  *
  * <pre><code>

--- a/testing/marionette/legacyaction.js
+++ b/testing/marionette/legacyaction.js
@@ -1,29 +1,30 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * 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/. */
 
-ChromeUtils.import("resource://gre/modules/Log.jsm");
 ChromeUtils.import("resource://gre/modules/Preferences.jsm");
+ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 
 const {
   element,
   WebElement,
 } = ChromeUtils.import("chrome://marionette/content/element.js", {});
 ChromeUtils.import("chrome://marionette/content/evaluate.js");
 ChromeUtils.import("chrome://marionette/content/event.js");
+const {Log} = ChromeUtils.import("chrome://marionette/content/log.js", {});
+
+XPCOMUtils.defineLazyGetter(this, "logger", Log.get);
 
 const CONTEXT_MENU_DELAY_PREF = "ui.click_hold_context_menus.delay";
 const DEFAULT_CONTEXT_MENU_DELAY = 750;  // ms
 
 this.EXPORTED_SYMBOLS = ["legacyaction"];
 
-const logger = Log.repository.getLogger("Marionette");
-
 /** @namespace */
 this.legacyaction = this.action = {};
 
 /**
  * Functionality for (single finger) action chains.
  */
 action.Chain = function() {
   // for assigning unique ids to all touches

--- a/testing/marionette/proxy.js
+++ b/testing/marionette/proxy.js
@@ -1,35 +1,34 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * 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";
 
-ChromeUtils.import("resource://gre/modules/Log.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 
 const {
   error,
   WebDriverError,
 } = ChromeUtils.import("chrome://marionette/content/error.js", {});
 ChromeUtils.import("chrome://marionette/content/evaluate.js");
+const {Log} = ChromeUtils.import("chrome://marionette/content/log.js", {});
 ChromeUtils.import("chrome://marionette/content/modal.js");
 const {
   MessageManagerDestroyedPromise,
 } = ChromeUtils.import("chrome://marionette/content/sync.js", {});
 
 this.EXPORTED_SYMBOLS = ["proxy"];
 
+XPCOMUtils.defineLazyGetter(this, "log", Log.get);
 XPCOMUtils.defineLazyServiceGetter(
     this, "uuidgen", "@mozilla.org/uuid-generator;1", "nsIUUIDGenerator");
 
-const log = Log.repository.getLogger("Marionette");
-
 // Proxy handler that traps requests to get a property.  Will prioritise
 // properties that exist on the object's own prototype.
 const ownPriorityGetterTrap = {
   get: (obj, prop) => {
     if (obj.hasOwnProperty(prop)) {
       return obj[prop];
     }
     return (...args) => obj.send(prop, args);

--- a/testing/marionette/reftest.js
+++ b/testing/marionette/reftest.js
@@ -1,29 +1,29 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * 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";
 
-ChromeUtils.import("resource://gre/modules/Log.jsm");
 ChromeUtils.import("resource://gre/modules/Preferences.jsm");
+ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 
 ChromeUtils.import("chrome://marionette/content/assert.js");
 ChromeUtils.import("chrome://marionette/content/capture.js");
-const {InvalidArgumentError} =
-    ChromeUtils.import("chrome://marionette/content/error.js", {});
+const {InvalidArgumentError} = ChromeUtils.import("chrome://marionette/content/error.js", {});
+const {Log} = ChromeUtils.import("chrome://marionette/content/log.js", {});
+
+XPCOMUtils.defineLazyGetter(this, "logger", Log.get);
 
 this.EXPORTED_SYMBOLS = ["reftest"];
 
 const XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
 const PREF_E10S = "browser.tabs.remote.autostart";
 
-const logger = Log.repository.getLogger("Marionette");
-
 const SCREENSHOT_MODE = {
   unexpected: 0,
   fail: 1,
   always: 2,
 };
 
 const STATUS = {
   PASS: "PASS",

--- a/testing/marionette/server.js
+++ b/testing/marionette/server.js
@@ -6,35 +6,36 @@
 
 const CC = Components.Constructor;
 
 const ServerSocket = CC(
     "@mozilla.org/network/server-socket;1",
     "nsIServerSocket",
     "initSpecialConnection");
 
-ChromeUtils.import("resource://gre/modules/Log.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
+ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 
 ChromeUtils.import("chrome://marionette/content/assert.js");
 const {GeckoDriver} = ChromeUtils.import("chrome://marionette/content/driver.js", {});
 const {WebElement} = ChromeUtils.import("chrome://marionette/content/element.js", {});
 const {
   error,
   UnknownCommandError,
 } = ChromeUtils.import("chrome://marionette/content/error.js", {});
 const {
   Command,
   Message,
   Response,
 } = ChromeUtils.import("chrome://marionette/content/message.js", {});
+const {Log} = ChromeUtils.import("chrome://marionette/content/log.js", {});
 const {MarionettePrefs} = ChromeUtils.import("chrome://marionette/content/prefs.js", {});
 const {DebuggerTransport} = ChromeUtils.import("chrome://marionette/content/transport.js", {});
 
-const logger = Log.repository.getLogger("Marionette");
+XPCOMUtils.defineLazyGetter(this, "logger", Log.get);
 
 const {KeepWhenOffline, LoopbackOnly} = Ci.nsIServerSocket;
 
 this.EXPORTED_SYMBOLS = [
   "TCPConnection",
   "TCPListener",
 ];
 

--- a/testing/marionette/sync.js
+++ b/testing/marionette/sync.js
@@ -1,33 +1,34 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * 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";
 
-ChromeUtils.import("resource://gre/modules/Log.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
+ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 
 const {
   error,
   TimeoutError,
 } = ChromeUtils.import("chrome://marionette/content/error.js", {});
+const {Log} = ChromeUtils.import("chrome://marionette/content/log.js", {});
+
+XPCOMUtils.defineLazyGetter(this, "logger", Log.get);
 
 this.EXPORTED_SYMBOLS = [
   /* exported PollPromise, TimedPromise */
   "PollPromise",
   "TimedPromise",
 
   /* exported MessageManagerDestroyedPromise */
   "MessageManagerDestroyedPromise",
 ];
 
-const logger = Log.repository.getLogger("Marionette");
-
 const {TYPE_ONE_SHOT, TYPE_REPEATING_SLACK} = Ci.nsITimer;
 
 /**
  * @callback Condition
  *
  * @param {function(*)} resolve
  *     To be called when the condition has been met.  Will return the
  *     resolved value.