diff --git a/extensions/apps-menu/extension.js b/extensions/apps-menu/extension.js
index 23da6c08..67ae6e97 100644
--- a/extensions/apps-menu/extension.js
+++ b/extensions/apps-menu/extension.js
@@ -677,22 +677,26 @@ class ApplicationsButton extends PanelMenu.Button {
     }
 }
 
-let appsMenuButton;
+class Extension {
+    constructor() {
+        ExtensionUtils.initTranslations();
+    }
 
-/** */
-function enable() {
-    appsMenuButton = new ApplicationsButton();
-    let index = Main.sessionMode.panel.left.indexOf('activities') + 1;
-    Main.panel.addToStatusArea('apps-menu', appsMenuButton, index, 'left');
-}
+    enable() {
+        this._appsMenuButton = new ApplicationsButton();
+        const index = Main.sessionMode.panel.left.indexOf('activities') + 1;
+        Main.panel.addToStatusArea(
+            'apps-menu', this._appsMenuButton, index, 'left');
+    }
 
-/** */
-function disable() {
-    Main.panel.menuManager.removeMenu(appsMenuButton.menu);
-    appsMenuButton.destroy();
+    disable() {
+        Main.panel.menuManager.removeMenu(this._appsMenuButton.menu);
+        this._appsMenuButton.destroy();
+        delete this._appsMenuButton;
+    }
 }
 
 /** */
 function init() {
-    ExtensionUtils.initTranslations();
+    return new Extension();
 }
diff --git a/extensions/auto-move-windows/extension.js b/extensions/auto-move-windows/extension.js
index 298de536..9362a52e 100644
--- a/extensions/auto-move-windows/extension.js
+++ b/extensions/auto-move-windows/extension.js
@@ -105,47 +105,46 @@ class WindowMover {
     }
 }
 
-let prevCheckWorkspaces;
-let winMover;
+class Extension {
+    enable() {
+        this._prevCheckWorkspaces = Main.wm._workspaceTracker._checkWorkspaces;
+        Main.wm._workspaceTracker._checkWorkspaces =
+            this._getCheckWorkspaceOverride(this._prevCheckWorkspaces);
+        this._windowMover = new WindowMover();
+    }
+
+    disable() {
+        Main.wm._workspaceTracker._checkWorkspaces = this._prevCheckWorkspaces;
+        this._windowMover.destroy();
+        delete this._windowMover;
+    }
+
+    _getCheckWorkspaceOverride(originalMethod) {
+        /* eslint-disable no-invalid-this */
+        return function () {
+            const keepAliveWorkspaces = [];
+            let foundNonEmpty = false;
+            for (let i = this._workspaces.length - 1; i >= 0; i--) {
+                if (!foundNonEmpty) {
+                    foundNonEmpty = this._workspaces[i].list_windows().some(
+                        w => !w.is_on_all_workspaces());
+                } else if (!this._workspaces[i]._keepAliveId) {
+                    keepAliveWorkspaces.push(this._workspaces[i]);
+                }
+            }
+
+            // make sure the original method only removes empty workspaces at the end
+            keepAliveWorkspaces.forEach(ws => (ws._keepAliveId = 1));
+            originalMethod.call(this);
+            keepAliveWorkspaces.forEach(ws => delete ws._keepAliveId);
+
+            return false;
+        };
+        /* eslint-enable no-invalid-this */
+    }
+}
 
 /** */
 function init() {
-    ExtensionUtils.initTranslations();
-}
-
-/**
- * @returns {bool} - false (used as MetaLater handler)
- */
-function myCheckWorkspaces() {
-    let keepAliveWorkspaces = [];
-    let foundNonEmpty = false;
-    for (let i = this._workspaces.length - 1; i >= 0; i--) {
-        if (!foundNonEmpty) {
-            foundNonEmpty = this._workspaces[i].list_windows().some(
-                w => !w.is_on_all_workspaces());
-        } else if (!this._workspaces[i]._keepAliveId) {
-            keepAliveWorkspaces.push(this._workspaces[i]);
-        }
-    }
-
-    // make sure the original method only removes empty workspaces at the end
-    keepAliveWorkspaces.forEach(ws => (ws._keepAliveId = 1));
-    prevCheckWorkspaces.call(this);
-    keepAliveWorkspaces.forEach(ws => delete ws._keepAliveId);
-
-    return false;
-}
-
-/** */
-function enable() {
-    prevCheckWorkspaces = Main.wm._workspaceTracker._checkWorkspaces;
-    Main.wm._workspaceTracker._checkWorkspaces = myCheckWorkspaces;
-
-    winMover = new WindowMover();
-}
-
-/** */
-function disable() {
-    Main.wm._workspaceTracker._checkWorkspaces = prevCheckWorkspaces;
-    winMover.destroy();
+    return new Extension();
 }
diff --git a/extensions/drive-menu/extension.js b/extensions/drive-menu/extension.js
index 45c854f4..fd98d989 100644
--- a/extensions/drive-menu/extension.js
+++ b/extensions/drive-menu/extension.js
@@ -212,20 +212,23 @@ class DriveMenu extends PanelMenu.Button {
     }
 }
 
+class Extension {
+    constructor() {
+        ExtensionUtils.initTranslations();
+    }
+
+    enable() {
+        this._indicator = new DriveMenu();
+        Main.panel.addToStatusArea('drive-menu', this._indicator);
+    }
+
+    disable() {
+        this._indicator.destroy();
+        delete this._indicator;
+    }
+}
+
 /** */
 function init() {
-    ExtensionUtils.initTranslations();
-}
-
-let _indicator;
-
-/** */
-function enable() {
-    _indicator = new DriveMenu();
-    Main.panel.addToStatusArea('drive-menu', _indicator);
-}
-
-/** */
-function disable() {
-    _indicator.destroy();
+    return new Extension();
 }
diff --git a/extensions/launch-new-instance/extension.js b/extensions/launch-new-instance/extension.js
index a249cd48..53f2420c 100644
--- a/extensions/launch-new-instance/extension.js
+++ b/extensions/launch-new-instance/extension.js
@@ -1,17 +1,25 @@
-/* exported enable disable */
+/* exported init */
 const AppDisplay = imports.ui.appDisplay;
 
-let _activateOriginal = null;
+class Extension {
+    constructor() {
+        this._appIconProto = AppDisplay.AppIcon.prototype;
+        this._activateOriginal = this._appIconProto.activate;
+    }
 
-/** */
-function enable() {
-    _activateOriginal = AppDisplay.AppIcon.prototype.activate;
-    AppDisplay.AppIcon.prototype.activate = function () {
-        _activateOriginal.call(this, 2);
-    };
+    enable() {
+        const {_activateOriginal} = this;
+        this._appIconProto.activate = function () {
+            _activateOriginal.call(this, 2);
+        };
+    }
+
+    disable() {
+        this._appIconProto.activate = this._activateOriginal;
+    }
 }
 
 /** */
-function disable() {
-    AppDisplay.AppIcon.prototype.activate = _activateOriginal;
+function init() {
+    return new Extension();
 }
diff --git a/extensions/native-window-placement/extension.js b/extensions/native-window-placement/extension.js
index b6b662a8..839464e2 100644
--- a/extensions/native-window-placement/extension.js
+++ b/extensions/native-window-placement/extension.js
@@ -236,75 +236,96 @@ class NaturalLayoutStrategy extends Workspace.LayoutStrategy {
     }
 }
 
-let winInjections, workspaceInjections;
+class Extension {
+    constructor() {
+        this._savedMethods = new Map();
+    }
 
-/** */
-function resetState() {
-    winInjections = { };
-    workspaceInjections = { };
+    enable() {
+        const settings = ExtensionUtils.getSettings();
+
+        const layoutProto = Workspace.WorkspaceLayout.prototype;
+        const previewProto = WindowPreview.prototype;
+
+        this._overrideMethod(layoutProto, '_createBestLayout', () => {
+            /* eslint-disable no-invalid-this */
+            return function () {
+                this._layoutStrategy = new NaturalLayoutStrategy({
+                    monitor: Main.layoutManager.monitors[this._monitorIndex],
+                }, settings);
+                return this._layoutStrategy.computeLayout(this._sortedWindows);
+            };
+            /* eslint-enable no-invalid-this */
+        });
+
+        // position window titles on top of windows in overlay
+        this._overrideMethod(previewProto, '_init', originalMethod => {
+            /* eslint-disable no-invalid-this */
+            return function (...args) {
+                originalMethod.call(this, ...args);
+
+                if (!settings.get_boolean('window-captions-on-top'))
+                    return;
+
+                const alignConstraint = this._title.get_constraints().find(
+                    c => c.align_axis && c.align_axis === Clutter.AlignAxis.Y_AXIS);
+                alignConstraint.factor = 0;
+
+                const bindConstraint = this._title.get_constraints().find(
+                    c => c.coordinate && c.coordinate === Clutter.BindCoordinate.Y);
+                bindConstraint.offset = 0;
+            };
+            /* eslint-enable no-invalid-this */
+        });
+
+        this._overrideMethod(previewProto, '_adjustOverlayOffsets', originalMethod => {
+            /* eslint-disable no-invalid-this */
+            return function (...args) {
+                originalMethod.call(this, ...args);
+
+                if (settings.get_boolean('window-captions-on-top'))
+                    this._title.translation_y = -this._title.translation_y;
+            };
+            /* eslint-enable no-invalid-this */
+        });
+    }
+
+    disable() {
+        this._restoreMethods();
+        global.stage.queue_relayout();
+    }
+
+    _saveMethod(prototype, methodName) {
+        let map = this._savedMethods.get(prototype);
+        if (!map) {
+            map = new Map();
+            this._savedMethods.set(prototype, map);
+        }
+
+        const originalMethod = prototype[methodName];
+        map.set(methodName, originalMethod);
+        return originalMethod;
+    }
+
+    _overrideMethod(prototype, methodName, createOverrideFunc) {
+        const originalMethod = this._saveMethod(prototype, methodName);
+        prototype[methodName] = createOverrideFunc(originalMethod);
+    }
+
+    _restoreMethods() {
+        for (const [proto, map] of this._savedMethods) {
+            for (const [methodName, originalMethod] of map) {
+                if (originalMethod === undefined)
+                    delete proto[methodName];
+                else
+                    proto[methodName] = originalMethod;
+            }
+        }
+        this._savedMethods.clear();
+    }
 }
 
 /** */
-function enable() {
-    resetState();
-
-    let settings = ExtensionUtils.getSettings();
-
-    workspaceInjections['_createBestLayout'] = Workspace.WorkspaceLayout.prototype._createBestLayout;
-    Workspace.WorkspaceLayout.prototype._createBestLayout = function (_area) {
-        this._layoutStrategy = new NaturalLayoutStrategy({
-            monitor: Main.layoutManager.monitors[this._monitorIndex],
-        }, settings);
-        return this._layoutStrategy.computeLayout(this._sortedWindows);
-    };
-
-    // position window titles on top of windows in overlay
-    winInjections['_init'] = WindowPreview.prototype._init;
-    WindowPreview.prototype._init = function (...args) {
-        winInjections['_init'].call(this, ...args);
-
-        if (!settings.get_boolean('window-captions-on-top'))
-            return;
-
-        const alignConstraint = this._title.get_constraints().find(
-            c => c.align_axis && c.align_axis === Clutter.AlignAxis.Y_AXIS);
-        alignConstraint.factor = 0;
-
-        const bindConstraint = this._title.get_constraints().find(
-            c => c.coordinate && c.coordinate === Clutter.BindCoordinate.Y);
-        bindConstraint.offset = 0;
-    };
-    winInjections['_adjustOverlayOffsets'] =
-        WindowPreview.prototype._adjustOverlayOffsets;
-    WindowPreview.prototype._adjustOverlayOffsets = function (...args) {
-        winInjections['_adjustOverlayOffsets'].call(this, ...args);
-
-        if (settings.get_boolean('window-captions-on-top'))
-            this._title.translation_y = -this._title.translation_y;
-    };
-}
-
-/**
- * @param {object} object - object that was modified
- * @param {object} injection - the map of previous injections
- * @param {string} name - the @injection key that should be removed
- */
-function removeInjection(object, injection, name) {
-    if (injection[name] === undefined)
-        delete object[name];
-    else
-        object[name] = injection[name];
-}
-
-/** */
-function disable() {
-    var i;
-
-    for (i in workspaceInjections)
-        removeInjection(Workspace.WorkspaceLayout.prototype, workspaceInjections, i);
-    for (i in winInjections)
-        removeInjection(WindowPreview.prototype, winInjections, i);
-
-    global.stage.queue_relayout();
-    resetState();
+function init() {
+    return new Extension();
 }
diff --git a/extensions/places-menu/extension.js b/extensions/places-menu/extension.js
index 7024ee30..d7fdab37 100644
--- a/extensions/places-menu/extension.js
+++ b/extensions/places-menu/extension.js
@@ -138,24 +138,27 @@ class PlacesMenu extends PanelMenu.Button {
     }
 }
 
+class Extension {
+    constructor() {
+        ExtensionUtils.initTranslations();
+    }
+
+    enable() {
+        this._indicator = new PlacesMenu();
+
+        let pos = Main.sessionMode.panel.left.length;
+        if ('apps-menu' in Main.panel.statusArea)
+            pos++;
+        Main.panel.addToStatusArea('places-menu', this._indicator, pos, 'left');
+    }
+
+    disable() {
+        this._indicator.destroy();
+        delete this._indicator;
+    }
+}
+
 /** */
 function init() {
-    ExtensionUtils.initTranslations();
-}
-
-let _indicator;
-
-/** */
-function enable() {
-    _indicator = new PlacesMenu();
-
-    let pos = Main.sessionMode.panel.left.length;
-    if ('apps-menu' in Main.panel.statusArea)
-        pos++;
-    Main.panel.addToStatusArea('places-menu', _indicator, pos, 'left');
-}
-
-/** */
-function disable() {
-    _indicator.destroy();
+    return new Extension();
 }
diff --git a/extensions/screenshot-window-sizer/extension.js b/extensions/screenshot-window-sizer/extension.js
index d59ec3f3..97354474 100644
--- a/extensions/screenshot-window-sizer/extension.js
+++ b/extensions/screenshot-window-sizer/extension.js
@@ -26,146 +26,145 @@ const Main = imports.ui.main;
 
 const MESSAGE_FADE_TIME = 2000;
 
-let text;
+class Extension {
+    SIZES = [
+        [624, 351],
+        [800, 450],
+        [1024, 576],
+        [1200, 675],
+        [1600, 900],
+        [360, 654], // Phone portrait maximized
+        [720, 360], // Phone landscape fullscreen
+    ];
 
-/** */
-function hideMessage() {
-    text.destroy();
-    text = null;
-}
-
-/**
- * @param {string} message - the message to flash
- */
-function flashMessage(message) {
-    if (!text) {
-        text = new St.Label({style_class: 'screenshot-sizer-message'});
-        Main.uiGroup.add_actor(text);
-    }
-
-    text.remove_all_transitions();
-    text.text = message;
-
-    text.opacity = 255;
-
-    let monitor = Main.layoutManager.primaryMonitor;
-    text.set_position(
-        monitor.x + Math.floor(monitor.width / 2 - text.width / 2),
-        monitor.y + Math.floor(monitor.height / 2 - text.height / 2));
-
-    text.ease({
-        opacity: 0,
-        duration: MESSAGE_FADE_TIME,
-        mode: Clutter.AnimationMode.EASE_OUT_QUAD,
-        onComplete: hideMessage,
-    });
-}
-
-let SIZES = [
-    [624, 351],
-    [800, 450],
-    [1024, 576],
-    [1200, 675],
-    [1600, 900],
-    [360, 654], // Phone portrait maximized
-    [720, 360], // Phone landscape fullscreen
-];
-
-/**
- * @param {Meta.Display} display - the display
- * @param {Meta.Window=} window - for per-window bindings, the window
- * @param {Meta.KeyBinding} binding - the key binding
- */
-function cycleScreenshotSizes(display, window, binding) {
-    // Probably this isn't useful with 5 sizes, but you can decrease instead
-    // of increase by holding down shift.
-    let modifiers = binding.get_modifiers();
-    let backwards = (modifiers & Meta.VirtualModifier.SHIFT_MASK) !== 0;
-
-    // Unmaximize first
-    if (window.get_maximized() !== 0)
-        window.unmaximize(Meta.MaximizeFlags.BOTH);
-
-    let workArea = window.get_work_area_current_monitor();
-    let outerRect = window.get_frame_rect();
-
-    // Double both axes if on a hidpi display
-    let scaleFactor = St.ThemeContext.get_for_stage(global.stage).scale_factor;
-    let scaledSizes = SIZES.map(size => size.map(wh => wh * scaleFactor))
-        .filter(([w, h]) => w <= workArea.width && h <= workArea.height);
-
-    // Find the nearest 16:9 size for the current window size
-    let nearestIndex;
-    let nearestError;
-
-    for (let i = 0; i < scaledSizes.length; i++) {
-        let [width, height] = scaledSizes[i];
-
-        // get the best initial window size
-        let error = Math.abs(width - outerRect.width) + Math.abs(height - outerRect.height);
-        if (nearestIndex === undefined || error < nearestError) {
-            nearestIndex = i;
-            nearestError = error;
+    _flashMessage(message) {
+        if (!this._text) {
+            this._text = new St.Label({style_class: 'screenshot-sizer-message'});
+            Main.uiGroup.add_actor(this._text);
         }
+
+        this._text.remove_all_transitions();
+        this._text.text = message;
+
+        this._text.opacity = 255;
+
+        const monitor = Main.layoutManager.primaryMonitor;
+        this._text.set_position(
+            monitor.x + Math.floor(monitor.width / 2 - this._text.width / 2),
+            monitor.y + Math.floor(monitor.height / 2 - this._text.height / 2));
+
+        this._text.ease({
+            opacity: 0,
+            duration: MESSAGE_FADE_TIME,
+            mode: Clutter.AnimationMode.EASE_OUT_QUAD,
+            onComplete: () => this._hideMessage(),
+        });
     }
 
-    // get the next size up or down from ideal
-    let newIndex = (nearestIndex + (backwards ? -1 : 1)) % scaledSizes.length;
-    let [newWidth, newHeight] = scaledSizes[newIndex];
+    _hideMessage() {
+        this._text.destroy();
+        delete this._text;
+    }
 
-    // Push the window onscreen if it would be resized offscreen
-    let newX = outerRect.x;
-    let newY = outerRect.y;
-    if (newX + newWidth > workArea.x + workArea.width)
-        newX = Math.max(workArea.x + workArea.width - newWidth);
-    if (newY + newHeight > workArea.y + workArea.height)
-        newY = Math.max(workArea.y + workArea.height - newHeight);
+    /**
+     * @param {Meta.Display} display - the display
+     * @param {Meta.Window=} window - for per-window bindings, the window
+     * @param {Meta.KeyBinding} binding - the key binding
+     */
+    _cycleScreenshotSizes(display, window, binding) {
+        // Probably this isn't useful with 5 sizes, but you can decrease instead
+        // of increase by holding down shift.
+        let modifiers = binding.get_modifiers();
+        let backwards = (modifiers & Meta.VirtualModifier.SHIFT_MASK) !== 0;
 
-    const id = window.connect('size-changed', () => {
-        window.disconnect(id);
-        _notifySizeChange(window);
-    });
-    window.move_resize_frame(true, newX, newY, newWidth, newHeight);
-}
+        // Unmaximize first
+        if (window.get_maximized() !== 0)
+            window.unmaximize(Meta.MaximizeFlags.BOTH);
 
-/**
- * @param {Meta.Window} window - the window whose size changed
- */
-function _notifySizeChange(window) {
-    const {scaleFactor} = St.ThemeContext.get_for_stage(global.stage);
-    let newOuterRect = window.get_frame_rect();
-    let message = '%d×%d'.format(
-        newOuterRect.width / scaleFactor,
-        newOuterRect.height / scaleFactor);
+        let workArea = window.get_work_area_current_monitor();
+        let outerRect = window.get_frame_rect();
 
-    // The new size might have been constrained by geometry hints (e.g. for
-    // a terminal) - in that case, include the actual ratio to the message
-    // we flash
-    let actualNumerator = 9 * newOuterRect.width / newOuterRect.height;
-    if (Math.abs(actualNumerator - 16) > 0.01)
-        message += ' (%.2f:9)'.format(actualNumerator);
+        // Double both axes if on a hidpi display
+        let scaleFactor = St.ThemeContext.get_for_stage(global.stage).scale_factor;
+        let scaledSizes = this.SIZES.map(size => size.map(wh => wh * scaleFactor))
+            .filter(([w, h]) => w <= workArea.width && h <= workArea.height);
 
-    flashMessage(message);
+        // Find the nearest 16:9 size for the current window size
+        let nearestIndex;
+        let nearestError;
+
+        for (let i = 0; i < scaledSizes.length; i++) {
+            let [width, height] = scaledSizes[i];
+
+            // get the best initial window size
+            let error = Math.abs(width - outerRect.width) + Math.abs(height - outerRect.height);
+            if (nearestIndex === undefined || error < nearestError) {
+                nearestIndex = i;
+                nearestError = error;
+            }
+        }
+
+        // get the next size up or down from ideal
+        let newIndex = (nearestIndex + (backwards ? -1 : 1)) % scaledSizes.length;
+        let [newWidth, newHeight] = scaledSizes[newIndex];
+
+        // Push the window onscreen if it would be resized offscreen
+        let newX = outerRect.x;
+        let newY = outerRect.y;
+        if (newX + newWidth > workArea.x + workArea.width)
+            newX = Math.max(workArea.x + workArea.width - newWidth);
+        if (newY + newHeight > workArea.y + workArea.height)
+            newY = Math.max(workArea.y + workArea.height - newHeight);
+
+        const id = window.connect('size-changed', () => {
+            window.disconnect(id);
+            this._notifySizeChange(window);
+        });
+        window.move_resize_frame(true, newX, newY, newWidth, newHeight);
+    }
+
+    /**
+     * @param {Meta.Window} window - the window whose size changed
+     */
+    _notifySizeChange(window) {
+        const {scaleFactor} = St.ThemeContext.get_for_stage(global.stage);
+        let newOuterRect = window.get_frame_rect();
+        let message = '%d×%d'.format(
+            newOuterRect.width / scaleFactor,
+            newOuterRect.height / scaleFactor);
+
+        // The new size might have been constrained by geometry hints (e.g. for
+        // a terminal) - in that case, include the actual ratio to the message
+        // we flash
+        let actualNumerator = 9 * newOuterRect.width / newOuterRect.height;
+        if (Math.abs(actualNumerator - 16) > 0.01)
+            message += ' (%.2f:9)'.format(actualNumerator);
+
+        this._flashMessage(message);
+    }
+
+    enable() {
+        Main.wm.addKeybinding(
+            'cycle-screenshot-sizes',
+            ExtensionUtils.getSettings(),
+            Meta.KeyBindingFlags.PER_WINDOW,
+            Shell.ActionMode.NORMAL,
+            this._cycleScreenshotSizes.bind(this));
+        Main.wm.addKeybinding(
+            'cycle-screenshot-sizes-backward',
+            ExtensionUtils.getSettings(),
+            Meta.KeyBindingFlags.PER_WINDOW | Meta.KeyBindingFlags.IS_REVERSED,
+            Shell.ActionMode.NORMAL,
+            this._cycleScreenshotSizes.bind(this));
+    }
+
+    disable() {
+        Main.wm.removeKeybinding('cycle-screenshot-sizes');
+        Main.wm.removeKeybinding('cycle-screenshot-sizes-backward');
+    }
 }
 
 /** */
-function enable() {
-    Main.wm.addKeybinding(
-        'cycle-screenshot-sizes',
-        ExtensionUtils.getSettings(),
-        Meta.KeyBindingFlags.PER_WINDOW,
-        Shell.ActionMode.NORMAL,
-        cycleScreenshotSizes);
-    Main.wm.addKeybinding(
-        'cycle-screenshot-sizes-backward',
-        ExtensionUtils.getSettings(),
-        Meta.KeyBindingFlags.PER_WINDOW | Meta.KeyBindingFlags.IS_REVERSED,
-        Shell.ActionMode.NORMAL,
-        cycleScreenshotSizes);
-}
-
-/** */
-function disable() {
-    Main.wm.removeKeybinding('cycle-screenshot-sizes');
-    Main.wm.removeKeybinding('cycle-screenshot-sizes-backward');
+function init() {
+    return new Extension();
 }
diff --git a/extensions/workspace-indicator/extension.js b/extensions/workspace-indicator/extension.js
index a9b3fd46..f3f1bb4d 100644
--- a/extensions/workspace-indicator/extension.js
+++ b/extensions/workspace-indicator/extension.js
@@ -454,20 +454,23 @@ class WorkspaceIndicator extends PanelMenu.Button {
     }
 }
 
+class Extension {
+    constructor() {
+        ExtensionUtils.initTranslations();
+    }
+
+    enable() {
+        this._indicator = new WorkspaceIndicator();
+        Main.panel.addToStatusArea('workspace-indicator', this._indicator);
+    }
+
+    disable() {
+        this._indicator.destroy();
+        delete this._indicator;
+    }
+}
+
 /** */
 function init() {
-    ExtensionUtils.initTranslations();
-}
-
-let _indicator;
-
-/** */
-function enable() {
-    _indicator = new WorkspaceIndicator();
-    Main.panel.addToStatusArea('workspace-indicator', _indicator);
-}
-
-/** */
-function disable() {
-    _indicator.destroy();
+    return new Extension();
 }